Internet Engineering Task Force (IETF) T. Mrugalski
Request for Comments: 8415 M. Siodelski
Obsoletes: 3315, 3633, 3736, 4242, 7083, ISC
7283, 7550 B. Volz
Category: Standards Track A. Yourtchenko
ISSN: 2070-1721 Cisco
M. Richardson
SSW
S. Jiang
Huawei
T. Lemon
Nibbhaya Consulting
T. Winters
UNH-IOL
November 2018
Internet Engineering Task Force (IETF) T. Mrugalski
Request for Comments: 8415 M. Siodelski
Obsoletes: 3315, 3633, 3736, 4242, 7083, ISC
7283, 7550 B. Volz
Category: Standards Track A. Yourtchenko
ISSN: 2070-1721 Cisco
M. Richardson
SSW
S. Jiang
Huawei
T. Lemon
Nibbhaya Consulting
T. Winters
UNH-IOL
November 2018
Dynamic Host Configuration Protocol for IPv6 (DHCPv6)
IPv6的动态主机配置协议（DHCPv6）
Abstract
摘要
This document describes the Dynamic Host Configuration Protocol for IPv6 (DHCPv6): an extensible mechanism for configuring nodes with network configuration parameters, IP addresses, and prefixes. Parameters can be provided statelessly, or in combination with stateful assignment of one or more IPv6 addresses and/or IPv6 prefixes. DHCPv6 can operate either in place of or in addition to stateless address autoconfiguration (SLAAC).
本文档描述了IPv6的动态主机配置协议（DHCPv6）：一种可扩展的机制，用于使用网络配置参数、IP地址和前缀配置节点。参数可以无状态提供，也可以与一个或多个IPv6地址和/或IPv6前缀的有状态分配结合使用。DHCPv6可以代替无状态地址自动配置（SLAAC）运行，也可以在无状态地址自动配置（SLAAC）之外运行。
This document updates the text from RFC 3315 (the original DHCPv6 specification) and incorporates prefix delegation (RFC 3633), stateless DHCPv6 (RFC 3736), an option to specify an upper bound for how long a client should wait before refreshing information (RFC 4242), a mechanism for throttling DHCPv6 clients when DHCPv6 service is not available (RFC 7083), and relay agent handling of unknown messages (RFC 7283). In addition, this document clarifies the interactions between models of operation (RFC 7550). As such, this document obsoletes RFC 3315, RFC 3633, RFC 3736, RFC 4242, RFC 7083, RFC 7283, and RFC 7550.
本文档更新了RFC 3315（原始DHCPv6规范）中的文本，并包含前缀委派（RFC 3633）、无状态DHCPv6（RFC 3736）、一个用于指定客户端在刷新信息之前应等待多长时间的上限的选项（RFC 4242）、一种在DHCPv6服务不可用时限制DHCPv6客户端的机制（RFC 7083）和中继代理处理未知消息（RFC 7283）。此外，本文档澄清了操作模型（RFC 7550）之间的交互。因此，本文档淘汰了RFC 3315、RFC 3633、RFC 3736、RFC 4242、RFC 7083、RFC 7283和RFC 7550。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 7841第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8415.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问https://www.rfc-editor.org/info/rfc8415.
Copyright Notice
版权公告
Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2018 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(https://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.
本文件可能包含2008年11月10日之前发布或公开的IETF文件或IETF贡献中的材料。控制某些材料版权的人员可能未授予IETF信托允许在IETF标准流程之外修改此类材料的权利。在未从控制此类材料版权的人员处获得充分许可的情况下，不得在IETF标准流程之外修改本文件，也不得在IETF标准流程之外创建其衍生作品，除了将其格式化以RFC形式发布或将其翻译成英语以外的其他语言。
Table of Contents
目录
1. Introduction ....................................................6
1.1. Relationship to Previous DHCPv6 Standards ..................7
1.2. Relationship to DHCPv4 .....................................8
2. Requirements ....................................................8
3. Background ......................................................8
4. Terminology .....................................................9
4.1. IPv6 Terminology ...........................................9
4.2. DHCP Terminology ..........................................11
5. Client/Server Exchanges ........................................16
5.1. Client/Server Exchanges Involving Two Messages ............16
5.2. Client/Server Exchanges Involving Four Messages ...........17
5.3. Server/Client Exchanges ...................................18
6. Operational Models .............................................18
6.1. Stateless DHCP ............................................18
6.2. DHCP for Non-temporary Address Assignment .................19
6.3. DHCP for Prefix Delegation ................................19
6.4. DHCP for Customer Edge Routers ............................22
6.5. DHCP for Temporary Addresses ..............................22
6.6. Multiple Addresses and Prefixes ...........................22
7. DHCP Constants .................................................23
7.1. Multicast Addresses .......................................23
7.2. UDP Ports .................................................24
7.3. DHCP Message Types ........................................24
7.4. DHCP Option Codes .........................................26
7.5. Status Codes ..............................................26
7.6. Transmission and Retransmission Parameters ................27
7.7. Representation of Time Values and "Infinity" as a
Time Value ................................................28
8. Client/Server Message Formats ..................................29
9. Relay Agent/Server Message Formats .............................30
9.1. Relay-forward Message .....................................31
9.2. Relay-reply Message .......................................31
10. Representation and Use of Domain Names ........................32
11. DHCP Unique Identifier (DUID) .................................32
11.1. DUID Contents ............................................33
11.2. DUID Based on Link-Layer Address Plus Time (DUID-LLT) ....33
11.3. DUID Assigned by Vendor Based on Enterprise
Number (DUID-EN) .........................................35
11.4. DUID Based on Link-Layer Address (DUID-LL) ...............36
11.5. DUID Based on Universally Unique Identifier (DUID-UUID) ..37
12. Identity Association ..........................................37
12.1. Identity Associations for Address Assignment .............38
12.2. Identity Associations for Prefix Delegation ..............38
1. Introduction ....................................................6
1.1. Relationship to Previous DHCPv6 Standards ..................7
1.2. Relationship to DHCPv4 .....................................8
2. Requirements ....................................................8
3. Background ......................................................8
4. Terminology .....................................................9
4.1. IPv6 Terminology ...........................................9
4.2. DHCP Terminology ..........................................11
5. Client/Server Exchanges ........................................16
5.1. Client/Server Exchanges Involving Two Messages ............16
5.2. Client/Server Exchanges Involving Four Messages ...........17
5.3. Server/Client Exchanges ...................................18
6. Operational Models .............................................18
6.1. Stateless DHCP ............................................18
6.2. DHCP for Non-temporary Address Assignment .................19
6.3. DHCP for Prefix Delegation ................................19
6.4. DHCP for Customer Edge Routers ............................22
6.5. DHCP for Temporary Addresses ..............................22
6.6. Multiple Addresses and Prefixes ...........................22
7. DHCP Constants .................................................23
7.1. Multicast Addresses .......................................23
7.2. UDP Ports .................................................24
7.3. DHCP Message Types ........................................24
7.4. DHCP Option Codes .........................................26
7.5. Status Codes ..............................................26
7.6. Transmission and Retransmission Parameters ................27
7.7. Representation of Time Values and "Infinity" as a
Time Value ................................................28
8. Client/Server Message Formats ..................................29
9. Relay Agent/Server Message Formats .............................30
9.1. Relay-forward Message .....................................31
9.2. Relay-reply Message .......................................31
10. Representation and Use of Domain Names ........................32
11. DHCP Unique Identifier (DUID) .................................32
11.1. DUID Contents ............................................33
11.2. DUID Based on Link-Layer Address Plus Time (DUID-LLT) ....33
11.3. DUID Assigned by Vendor Based on Enterprise
Number (DUID-EN) .........................................35
11.4. DUID Based on Link-Layer Address (DUID-LL) ...............36
11.5. DUID Based on Universally Unique Identifier (DUID-UUID) ..37
12. Identity Association ..........................................37
12.1. Identity Associations for Address Assignment .............38
12.2. Identity Associations for Prefix Delegation ..............38
13. Assignment to an IA ...........................................39
13.1. Selecting Addresses for Assignment to an IA_NA ...........39
13.2. Assignment of Temporary Addresses ........................40
13.3. Assignment of Prefixes for IA_PD .........................41
14. Transmission of Messages by a Client ..........................41
14.1. Rate Limiting ............................................41
14.2. Client Behavior when T1 and/or T2 Are 0 ..................42
15. Reliability of Client-Initiated Message Exchanges .............43
16. Message Validation ............................................45
16.1. Use of Transaction IDs ...................................45
16.2. Solicit Message ..........................................46
16.3. Advertise Message ........................................46
16.4. Request Message ..........................................46
16.5. Confirm Message ..........................................47
16.6. Renew Message ............................................47
16.7. Rebind Message ...........................................47
16.8. Decline Message ..........................................47
16.9. Release Message ..........................................48
16.10. Reply Message ...........................................48
16.11. Reconfigure Message .....................................48
16.12. Information-request Message .............................49
16.13. Relay-forward Message ...................................49
16.14. Relay-reply Message .....................................49
17. Client Source Address and Interface Selection .................49
17.1. Source Address and Interface Selection for
Address Assignment .......................................49
17.2. Source Address and Interface Selection for Prefix
Delegation ...............................................50
18. DHCP Configuration Exchanges ..................................50
18.1. A Single Exchange for Multiple IA Options ................53
18.2. Client Behavior ..........................................53
18.2.1. Creation and Transmission of Solicit Messages .....55
18.2.2. Creation and Transmission of Request Messages .....57
18.2.3. Creation and Transmission of Confirm Messages .....59
18.2.4. Creation and Transmission of Renew Messages .......60
18.2.5. Creation and Transmission of Rebind Messages ......62
18.2.6. Creation and Transmission of
Information-request Messages ......................63
18.2.7. Creation and Transmission of Release Messages .....64
18.2.8. Creation and Transmission of Decline Messages .....65
18.2.9. Receipt of Advertise Messages .....................67
18.2.10. Receipt of Reply Messages ........................68
18.2.10.1. Reply for Solicit (with Rapid
Commit), Request, Renew, or Rebind ......69
18.2.10.2. Reply for Release and Decline ...........72
18.2.10.3. Reply for Confirm .......................72
18.2.10.4. Reply for Information-request ...........72
13. Assignment to an IA ...........................................39
13.1. Selecting Addresses for Assignment to an IA_NA ...........39
13.2. Assignment of Temporary Addresses ........................40
13.3. Assignment of Prefixes for IA_PD .........................41
14. Transmission of Messages by a Client ..........................41
14.1. Rate Limiting ............................................41
14.2. Client Behavior when T1 and/or T2 Are 0 ..................42
15. Reliability of Client-Initiated Message Exchanges .............43
16. Message Validation ............................................45
16.1. Use of Transaction IDs ...................................45
16.2. Solicit Message ..........................................46
16.3. Advertise Message ........................................46
16.4. Request Message ..........................................46
16.5. Confirm Message ..........................................47
16.6. Renew Message ............................................47
16.7. Rebind Message ...........................................47
16.8. Decline Message ..........................................47
16.9. Release Message ..........................................48
16.10. Reply Message ...........................................48
16.11. Reconfigure Message .....................................48
16.12. Information-request Message .............................49
16.13. Relay-forward Message ...................................49
16.14. Relay-reply Message .....................................49
17. Client Source Address and Interface Selection .................49
17.1. Source Address and Interface Selection for
Address Assignment .......................................49
17.2. Source Address and Interface Selection for Prefix
Delegation ...............................................50
18. DHCP Configuration Exchanges ..................................50
18.1. A Single Exchange for Multiple IA Options ................53
18.2. Client Behavior ..........................................53
18.2.1. Creation and Transmission of Solicit Messages .....55
18.2.2. Creation and Transmission of Request Messages .....57
18.2.3. Creation and Transmission of Confirm Messages .....59
18.2.4. Creation and Transmission of Renew Messages .......60
18.2.5. Creation and Transmission of Rebind Messages ......62
18.2.6. Creation and Transmission of
Information-request Messages ......................63
18.2.7. Creation and Transmission of Release Messages .....64
18.2.8. Creation and Transmission of Decline Messages .....65
18.2.9. Receipt of Advertise Messages .....................67
18.2.10. Receipt of Reply Messages ........................68
18.2.10.1. Reply for Solicit (with Rapid
Commit), Request, Renew, or Rebind ......69
18.2.10.2. Reply for Release and Decline ...........72
18.2.10.3. Reply for Confirm .......................72
18.2.10.4. Reply for Information-request ...........72
18.2.11. Receipt of Reconfigure Messages ..................72
18.2.12. Refreshing Configuration Information .............73
18.3. Server Behavior ..........................................74
18.3.1. Receipt of Solicit Messages .......................75
18.3.2. Receipt of Request Messages .......................77
18.3.3. Receipt of Confirm Messages .......................79
18.3.4. Receipt of Renew Messages .........................79
18.3.5. Receipt of Rebind Messages ........................81
18.3.6. Receipt of Information-request Messages ...........83
18.3.7. Receipt of Release Messages .......................84
18.3.8. Receipt of Decline Messages .......................85
18.3.9. Creation of Advertise Messages ....................85
18.3.10. Transmission of Advertise and Reply Messages .....87
18.3.11. Creation and Transmission of Reconfigure
Messages .........................................87
18.4. Reception of Unicast Messages ............................88
19. Relay Agent Behavior ..........................................89
19.1. Relaying a Client Message or a Relay-forward Message .....89
19.1.1. Relaying a Message from a Client ..................90
19.1.2. Relaying a Message from a Relay Agent .............90
19.1.3. Relay Agent Behavior with Prefix Delegation .......91
19.2. Relaying a Relay-reply Message ...........................91
19.3. Construction of Relay-reply Messages .....................91
19.4. Interaction between Relay Agents and Servers .............92
20. Authentication of DHCP Messages ...............................93
20.1. Security of Messages Sent between Servers and
Relay Agents .............................................94
20.2. Summary of DHCP Authentication ...........................94
20.3. Replay Detection .........................................94
20.4. Reconfiguration Key Authentication Protocol (RKAP) .......95
20.4.1. Use of the Authentication Option in RKAP ..........96
20.4.2. Server Considerations for RKAP ....................96
20.4.3. Client Considerations for RKAP ....................97
21. DHCP Options ..................................................97
21.1. Format of DHCP Options ...................................98
21.2. Client Identifier Option .................................99
21.3. Server Identifier Option .................................99
21.4. Identity Association for Non-temporary Addresses
Option ..................................................100
21.5. Identity Association for Temporary Addresses Option .....102
21.6. IA Address Option .......................................104
21.7. Option Request Option ...................................106
21.8. Preference Option .......................................108
21.9. Elapsed Time Option .....................................108
21.10. Relay Message Option ...................................109
21.11. Authentication Option ..................................110
21.12. Server Unicast Option ..................................111
21.13. Status Code Option .....................................112
18.2.11. Receipt of Reconfigure Messages ..................72
18.2.12. Refreshing Configuration Information .............73
18.3. Server Behavior ..........................................74
18.3.1. Receipt of Solicit Messages .......................75
18.3.2. Receipt of Request Messages .......................77
18.3.3. Receipt of Confirm Messages .......................79
18.3.4. Receipt of Renew Messages .........................79
18.3.5. Receipt of Rebind Messages ........................81
18.3.6. Receipt of Information-request Messages ...........83
18.3.7. Receipt of Release Messages .......................84
18.3.8. Receipt of Decline Messages .......................85
18.3.9. Creation of Advertise Messages ....................85
18.3.10. Transmission of Advertise and Reply Messages .....87
18.3.11. Creation and Transmission of Reconfigure
Messages .........................................87
18.4. Reception of Unicast Messages ............................88
19. Relay Agent Behavior ..........................................89
19.1. Relaying a Client Message or a Relay-forward Message .....89
19.1.1. Relaying a Message from a Client ..................90
19.1.2. Relaying a Message from a Relay Agent .............90
19.1.3. Relay Agent Behavior with Prefix Delegation .......91
19.2. Relaying a Relay-reply Message ...........................91
19.3. Construction of Relay-reply Messages .....................91
19.4. Interaction between Relay Agents and Servers .............92
20. Authentication of DHCP Messages ...............................93
20.1. Security of Messages Sent between Servers and
Relay Agents .............................................94
20.2. Summary of DHCP Authentication ...........................94
20.3. Replay Detection .........................................94
20.4. Reconfiguration Key Authentication Protocol (RKAP) .......95
20.4.1. Use of the Authentication Option in RKAP ..........96
20.4.2. Server Considerations for RKAP ....................96
20.4.3. Client Considerations for RKAP ....................97
21. DHCP Options ..................................................97
21.1. Format of DHCP Options ...................................98
21.2. Client Identifier Option .................................99
21.3. Server Identifier Option .................................99
21.4. Identity Association for Non-temporary Addresses
Option ..................................................100
21.5. Identity Association for Temporary Addresses Option .....102
21.6. IA Address Option .......................................104
21.7. Option Request Option ...................................106
21.8. Preference Option .......................................108
21.9. Elapsed Time Option .....................................108
21.10. Relay Message Option ...................................109
21.11. Authentication Option ..................................110
21.12. Server Unicast Option ..................................111
21.13. Status Code Option .....................................112
21.14. Rapid Commit Option ....................................114
21.15. User Class Option ......................................115
21.16. Vendor Class Option ....................................116
21.17. Vendor-specific Information Option .....................117
21.18. Interface-Id Option ....................................119
21.19. Reconfigure Message Option .............................121
21.20. Reconfigure Accept Option ..............................121
21.21. Identity Association for Prefix Delegation Option ......122
21.22. IA Prefix Option .......................................124
21.23. Information Refresh Time Option ........................126
21.24. SOL_MAX_RT Option ......................................127
21.25. INF_MAX_RT Option ......................................128
22. Security Considerations ......................................130
23. Privacy Considerations .......................................133
24. IANA Considerations ..........................................133
25. Obsoleted Mechanisms .........................................138
26. References ...................................................139
26.1. Normative References ....................................139
26.2. Informative References ..................................140
Appendix A. Summary of Changes ...................................146
Appendix B. Appearance of Options in Message Types ...............149
Appendix C. Appearance of Options in the "options" Field of DHCP
Options ..............................................151
Acknowledgments ..................................................152
Authors' Addresses ...............................................153
21.14. Rapid Commit Option ....................................114
21.15. User Class Option ......................................115
21.16. Vendor Class Option ....................................116
21.17. Vendor-specific Information Option .....................117
21.18. Interface-Id Option ....................................119
21.19. Reconfigure Message Option .............................121
21.20. Reconfigure Accept Option ..............................121
21.21. Identity Association for Prefix Delegation Option ......122
21.22. IA Prefix Option .......................................124
21.23. Information Refresh Time Option ........................126
21.24. SOL_MAX_RT Option ......................................127
21.25. INF_MAX_RT Option ......................................128
22. Security Considerations ......................................130
23. Privacy Considerations .......................................133
24. IANA Considerations ..........................................133
25. Obsoleted Mechanisms .........................................138
26. References ...................................................139
26.1. Normative References ....................................139
26.2. Informative References ..................................140
Appendix A. Summary of Changes ...................................146
Appendix B. Appearance of Options in Message Types ...............149
Appendix C. Appearance of Options in the "options" Field of DHCP
Options ..............................................151
Acknowledgments ..................................................152
Authors' Addresses ...............................................153
This document describes DHCP for IPv6 (DHCPv6), a client/server protocol that provides managed configuration of devices. The basic operation of DHCPv6 provides configuration for clients connected to the same link as the server. Relay agent functionality is also defined for enabling communication between clients and servers that are not on the same link.
本文档介绍了DHCP for IPv6（DHCPv6），这是一种提供设备托管配置的客户机/服务器协议。DHCPv6的基本操作为连接到与服务器相同链路的客户端提供配置。中继代理功能还定义为支持不在同一链路上的客户端和服务器之间的通信。
DHCPv6 can provide a device with addresses assigned by a DHCPv6 server and other configuration information; this data is carried in options. DHCPv6 can be extended through the definition of new options to carry configuration information not specified in this document.
DHCPv6可以向设备提供DHCPv6服务器分配的地址和其他配置信息；这些数据在选项中携带。可以通过定义新选项来扩展DHCPv6，以携带本文档中未指定的配置信息。
DHCPv6 also provides a mechanism for automated delegation of IPv6 prefixes using DHCPv6, as originally specified in [RFC3633]. Through this mechanism, a delegating router can delegate prefixes to requesting routers. Use of this mechanism is specified as part of [RFC7084] and by [TR-187].
DHCPv6还提供了一种使用DHCPv6自动委派IPv6前缀的机制，如[RFC3633]中最初所述。通过这种机制，委托路由器可以将前缀委托给请求路由器。[RFC7084]和[TR-187]规定了该机制的使用。
DHCP can also be used just to provide other configuration options (i.e., no addresses or prefixes). That implies that the server does not have to track any state; thus, this mode is called "stateless DHCPv6". Mechanisms necessary to support stateless DHCPv6 are much smaller than mechanisms needed to support stateful DHCPv6. [RFC3736] was written to document just those portions of DHCPv6 needed to support DHCPv6 stateless operation.
DHCP还可以仅用于提供其他配置选项（即，没有地址或前缀）。这意味着服务器不必跟踪任何状态；因此，这种模式被称为“无状态DHCPv6”。支持无状态DHCPv6所需的机制比支持有状态DHCPv6所需的机制小得多。[RFC3736]编写的目的就是记录支持DHCPv6无状态操作所需的DHCPv6部分。
The remainder of this introduction summarizes the relationship to the previous DHCPv6 standards (see Section 1.1) and clarifies the stance with regard to DHCPv4 (see Section 1.2). Section 5 describes the message exchange mechanisms to illustrate DHCP operation rather than provide an exhaustive list of all possible interactions, and Section 6 provides an overview of common operational models. Section 18 explains client and server operation in detail.
本简介的其余部分总结了与先前DHCPv6标准的关系（见第1.1节），并澄清了与DHCPv4相关的立场（见第1.2节）。第5节描述了用于说明DHCP操作的消息交换机制，而不是提供所有可能交互的详尽列表，第6节概述了常见的操作模型。第18节详细解释了客户端和服务器的操作。
The initial specification of DHCPv6 was defined in [RFC3315], and a number of follow-up documents were published over the years:
[RFC3315]中定义了DHCPv6的初始规范，多年来发布了许多后续文件：
- [RFC3633] ("IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6")
- [RFC3633]（“动态主机配置协议（DHCP）版本6的IPv6前缀选项”）
- [RFC3736] ("Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6")
- [RFC3736]（“IPv6的无状态动态主机配置协议（DHCP）服务”）
- [RFC4242] ("Information Refresh Time Option for Dynamic Host Configuration Protocol for IPv6 (DHCPv6)")
- [RFC4242]（“IPv6（DHCPv6）动态主机配置协议的信息刷新时间选项”）
- [RFC7083] ("Modification to Default Values of SOL_MAX_RT and INF_MAX_RT")
- [RFC7083]（“修改SOL_MAX_RT和INF_MAX_RT的默认值”）
- [RFC7283] ("Handling Unknown DHCPv6 Messages")
- [RFC7283]（“处理未知DHCPv6消息”）
- [RFC7550] ("Issues and Recommendations with Multiple Stateful DHCPv6 Options")
- [RFC7550]（“多状态DHCPv6选项的问题和建议”）
This document provides a unified, corrected, and cleaned-up definition of DHCPv6 that also covers all applicable errata filed against older RFCs (see the list in Appendix A). As such, it obsoletes the RFCs listed in the previous paragraph. Also, there are a small number of mechanisms that were obsoleted; see Section 25 and Appendix A.
本文件提供了DHCPv6的统一、更正和清理定义，还涵盖了针对旧RFC提交的所有适用勘误表（见附录a中的列表）。因此，它淘汰了上一段中列出的RFC。此外，还有少数机制已经过时；见第25节和附录A。
The operational models and relevant configuration information for DHCPv4 [RFC2131] [RFC2132] and DHCPv6 are sufficiently different that integration between the two services is not included in this document. [RFC3315] suggested that future work might be to extend DHCPv6 to carry IPv4 address and configuration information. However, the current consensus of the IETF is that DHCPv4 should be used rather than DHCPv6 when conveying IPv4 configuration information to nodes. For IPv6-only networks, [RFC7341] describes a transport mechanism to carry DHCPv4 messages using the DHCPv6 protocol for the dynamic provisioning of IPv4 address and configuration information.
DHCPv4[RFC2131][RFC2132]和DHCPv6的操作模型和相关配置信息完全不同，因此本文档中不包括两个服务之间的集成。[RFC3315]建议未来的工作可能是扩展DHCPv6以承载IPv4地址和配置信息。然而，IETF目前的共识是，在向节点传输IPv4配置信息时，应使用DHCPv4而不是DHCPv6。对于仅限IPv6的网络，[RFC7341]描述了一种传输机制，该机制使用DHCPv6协议来承载DHCPv4消息，以便动态提供IPv4地址和配置信息。
Merging DHCPv4 and DHCPv6 configuration is out of scope for this document. [RFC4477] discusses some issues and possible strategies for running DHCPv4 and DHCPv6 services together. While [RFC4477] is a bit dated, it provides a good overview of the issues at hand.
合并DHCPv4和DHCPv6配置超出了本文档的范围。[RFC4477]讨论了一起运行DHCPv4和DHCPv6服务的一些问题和可能的策略。虽然[RFC4477]有点过时，但它很好地概述了当前的问题。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”在所有大写字母出现时（如图所示）应按照BCP 14[RFC2119][RFC8174]所述进行解释。
This document also makes use of internal conceptual variables to describe protocol behavior and external variables that an implementation must allow system administrators to change. The specific variable names, how their values change, and how their settings influence protocol behavior are provided to demonstrate protocol behavior. An implementation is not required to have them in the exact form described here, as long as its external behavior is consistent with that described in this document.
本文档还使用内部概念变量来描述协议行为和实现必须允许系统管理员更改的外部变量。提供特定变量名称、其值如何更改以及其设置如何影响协议行为，以演示协议行为。只要实现的外部行为与本文档中描述的一致，就不要求实现的外部行为与本文中描述的完全相同。
[RFC8200] ("Internet Protocol, Version 6 (IPv6) Specification") provides the base architecture and design of IPv6. In addition to [RFC8200], related work in IPv6 that an implementer would be best served to study includes
[RFC8200]（“互联网协议，第6版（IPv6）规范”）提供了IPv6的基本架构和设计。除了[RFC8200]之外，实现者最好研究的IPv6相关工作包括
- [RFC4291] ("IP Version 6 Addressing Architecture")
- [RFC4291]（“IP版本6寻址体系结构”）
- [RFC4862] ("IPv6 Stateless Address Autoconfiguration")
- [RFC4862]（“IPv6无状态地址自动配置”）
- [RFC4861] ("Neighbor Discovery for IP version 6 (IPv6)")
- [RFC4861]（“IP版本6（IPv6）的邻居发现”）
These specifications enable DHCP to build upon the IPv6 work to provide robust stateful autoconfiguration.
这些规范使DHCP能够在IPv6工作的基础上构建，以提供健壮的有状态自动配置。
[RFC4291] defines the address scope that can be used in an IPv6 implementation and also provides various configuration architecture guidelines for network designers of the IPv6 address space. Two advantages of IPv6 are that support for multicast is required and nodes can create link-local addresses during initialization. The availability of these features means that a client can use its link-local address and a well-known multicast address to discover and communicate with DHCP servers or relay agents on its link.
[RFC4291]定义了可在IPv6实施中使用的地址范围，并为IPv6地址空间的网络设计者提供了各种配置体系结构指南。IPv6的两个优点是需要对多播的支持，并且节点可以在初始化期间创建链路本地地址。这些功能的可用性意味着客户端可以使用其链路本地地址和众所周知的多播地址来发现其链路上的DHCP服务器或中继代理并与之通信。
[RFC4862] specifies procedures by which a node may autoconfigure addresses based on Router Advertisements [RFC4861] and the use of a valid lifetime to support renumbering of addresses on the Internet. Compatibility with stateless address autoconfiguration is a design requirement of DHCP.
[RFC4862]指定了一个过程，通过该过程，节点可以根据路由器公告[RFC4861]和有效生存期的使用来自动配置地址，以支持对Internet上的地址重新编号。与无状态地址自动配置的兼容性是DHCP的设计要求。
IPv6 Neighbor Discovery [RFC4861] is the node discovery protocol in IPv6 that replaces and enhances functions of ARP [RFC826]. To understand IPv6 and stateless address autoconfiguration, it is strongly recommended that implementers understand IPv6 Neighbor Discovery.
IPv6邻居发现[RFC4861]是IPv6中的节点发现协议，它取代并增强了ARP[RFC826]的功能。要了解IPv6和无状态地址自动配置，强烈建议实施者了解IPv6邻居发现。
This section defines terminology specific to IPv6 and DHCP used in this document.
本节定义了本文档中使用的特定于IPv6和DHCP的术语。
IPv6 terminology from [RFC8200], [RFC4291], and [RFC4862] relevant to this specification is included below.
[RFC8200]、[RFC4291]和[RFC4862]中与本规范相关的IPv6术语包括在下面。
address An IP-layer identifier for an interface or a set of interfaces.
地址一个接口或一组接口的IP层标识符。
GUA Global unicast address (see [RFC4291]).
GUA全局单播地址（参见[RFC4291]）。
host Any node that is not a router.
托管不是路由器的任何节点。
IP Internet Protocol Version 6 (IPv6). The terms "IPv4" and "IPv6" are used only in contexts where it is necessary to avoid ambiguity.
IP Internet Protocol Version 6 (IPv6). The terms "IPv4" and "IPv6" are used only in contexts where it is necessary to avoid ambiguity.translate error, please retry
interface A node's attachment to a link.
将节点的附件连接到链接。
link A communication facility or medium over which nodes can communicate at the link layer, i.e., the layer immediately below IP. Examples are Ethernet (simple or bridged); Point-to-Point Protocol (PPP) and PPP over Ethernet (PPPoE) links; and Internet-layer (or higher) "tunnels", such as tunnels over IPv4 or IPv6 itself.
链路节点可在链路层（即IP下的一层）上进行通信的通信设施或介质。例如以太网（简单或桥接）；点对点协议（PPP）和以太网PPP（PPPoE）链路；和Internet层（或更高级别）“隧道”，例如IPv4或IPv6本身上的隧道。
link-layer identifier A link-layer identifier for an interface -- for example, IEEE 802 addresses for Ethernet or Token Ring network interfaces.
链路层标识符接口的链路层标识符——例如，以太网或令牌环网接口的IEEE 802地址。
link-local address An IPv6 address having a link-only scope, indicated by having the prefix (fe80::/10), that can be used to reach neighboring nodes attached to the same link. Every IPv6 interface on which DHCPv6 can reasonably be useful has a link-local address.
链路本地地址具有仅链路作用域的IPv6地址，由前缀（fe80:：/10）表示，可用于到达连接到同一链路的相邻节点。DHCPv6可以合理使用的每个IPv6接口都有一个链路本地地址。
multicast address An identifier for a set of interfaces (typically belonging to different nodes). A packet sent to a multicast address is delivered to all interfaces identified by that address.
多播地址一组接口（通常属于不同节点）的标识符。发送到多播地址的数据包被发送到该地址标识的所有接口。
neighbor A node attached to the same link.
邻居连接到同一链路的节点。
node A device that implements IP.
节点实现IP的设备。
packet An IP header plus payload.
一个IP报头加上有效负载的数据包。
prefix The initial bits of an address, or a set of IP addresses that share the same initial bits.
前缀地址的初始位，或共享相同初始位的一组IP地址。
prefix length The number of bits in a prefix.
前缀长度前缀中的位数。
router A node that forwards IP packets not explicitly addressed to itself.
路由器转发未显式寻址到自身的IP数据包的节点。
ULA Unique local address (see [RFC4193]).
唯一本地地址（参见[RFC4193]）。
unicast address An identifier for a single interface. A packet sent to a unicast address is delivered to the interface identified by that address.
单播地址单个接口的标识符。发送到单播地址的数据包被发送到由该地址标识的接口。
Terminology specific to DHCP can be found below.
DHCP专用术语见下文。
appropriate to the link An address is "appropriate to the link" when the address is consistent with the DHCP server's knowledge of the network topology, prefix assignment, and address assignment policies.
适用于链路当地址与DHCP服务器对网络拓扑、前缀分配和地址分配策略的了解一致时，地址为“适用于链路”。
binding A binding (or client binding) is a group of server data records containing the information the server has about the addresses or delegated prefixes in an Identity Association (IA) or configuration information explicitly assigned to the client. Configuration information that has been returned to a client through a policy, such as the information returned to all clients on the same link, does not require a binding. A binding containing information about an IA is indexed by the tuple <DUID, IA-type, IAID> (where IA-type is the type of lease in the IA -- for example, temporary). A binding containing configuration information for a client is indexed by <DUID>. See below for definitions of DUID, IA, and IAID.
绑定绑定（或客户端绑定）是一组服务器数据记录，其中包含服务器关于标识关联（IA）中的地址或委派前缀的信息，或显式分配给客户端的配置信息。通过策略返回给客户端的配置信息（例如返回给同一链接上所有客户端的信息）不需要绑定。包含IA相关信息的绑定由元组<DUID，IA type，IAID>索引（其中IA type是IA中的租约类型，例如临时租约）。包含客户端配置信息的绑定由<DUID>索引。有关DUID、IA和IAID的定义，请参见下文。
configuration parameter An element of the configuration information set on the server and delivered to the client using DHCP. Such parameters may be used to carry information to be used by a node to configure its network subsystem and enable communication on a link or internetwork, for example.
配置参数服务器上设置的配置信息的元素，并使用DHCP传递给客户端。例如，这些参数可用于携带节点用于配置其网络子系统和启用链路或互联网上的通信的信息。
container option An option that encapsulates other options (for example, the IA_NA option (see Section 21.4) may contain IA Address options (see Section 21.6)).
容器选项封装其他选项的选项（例如，IA_NA选项（参见第21.4节）可能包含IA地址选项（参见第21.6节））。
delegating router The router that acts as a DHCP server and responds to requests for delegated prefixes. This document primarily uses the term "DHCP server" or "server" when discussing the "delegating router" functionality of prefix delegation (see Section 1).
委派路由器充当DHCP服务器并响应委派前缀请求的路由器。在讨论前缀委派的“委派路由器”功能时，本文档主要使用术语“DHCP服务器”或“服务器”（见第1节）。
DHCP Dynamic Host Configuration Protocol for IPv6. The terms "DHCPv4" and "DHCPv6" are used only in contexts where it is necessary to avoid ambiguity.
IPv6的DHCP动态主机配置协议。术语“DHCPv4”和“DHCPv6”仅在需要避免歧义的上下文中使用。
DHCP client Also referred to as "client". A node that initiates requests on a link to obtain configuration parameters from one or more DHCP servers. The node may act as a requesting router (see below) if it supports prefix delegation.
DHCP客户端也称为“客户端”。在链路上发起请求以从一个或多个DHCP服务器获取配置参数的节点。如果节点支持前缀委派，则可以充当请求路由器（见下文）。
DHCP domain A set of links managed by DHCP and operated by a single administrative entity.
DHCP域由DHCP管理并由单个管理实体操作的一组链接。
DHCP relay agent Also referred to as "relay agent". A node that acts as an intermediary to deliver DHCP messages between clients and servers. In certain configurations, there may be more than one relay agent between clients and servers, so a relay agent may send DHCP messages to another relay agent.
DHCP中继代理也称为“中继代理”。作为中介在客户端和服务器之间传递DHCP消息的节点。在某些配置中，客户端和服务器之间可能有多个中继代理，因此中继代理可以向另一个中继代理发送DHCP消息。
DHCP server Also referred to as "server". A node that responds to requests from clients. It may or may not be on the same link as the client(s). Depending on its capabilities, if it supports prefix delegation it may also feature the functionality of a delegating router.
DHCP服务器也称为“服务器”。响应客户端请求的节点。它可能与客户端位于同一链路上，也可能与客户端不在同一链路上。根据其功能，如果它支持前缀委派，它还可能具有委派路由器的功能。
DUID A DHCP Unique Identifier for a DHCP participant. Each DHCP client and server has exactly one DUID. See Section 11 for details of the ways in which a DUID may be constructed.
DUID DHCP参与者的DHCP唯一标识符。每个DHCP客户端和服务器只有一个DUID。有关DUID构造方式的详细信息，请参见第11节。
encapsulated option A DHCP option that is usually only contained in another option. For example, the IA Address option is contained in IA_NA or IA_TA options (see Section 21.5). See Section 9 of [RFC7227] for a more complete definition.
封装选项通常仅包含在另一个选项中的DHCP选项。例如，IA地址选项包含在IA_NA或IA_TA选项中（参见第21.5节）。有关更完整的定义，请参见[RFC7227]第9节。
IA Identity Association: a collection of leases assigned to a client. Each IA has an associated IAID (see below). A client may have more than one IA assigned to it -- for example, one for each of its interfaces. Each IA holds one type of lease; for example, an identity association for temporary addresses (IA_TA) holds temporary addresses, and an identity association for prefix delegation (IA_PD) holds delegated prefixes. Throughout this document, "IA" is used to refer to an identity association without identifying the type of a lease in the IA. At the time of writing this document, there are three IA types defined: IA_NA, IA_TA, and IA_PD. New IA types may be defined in the future.
IA标识关联：分配给客户的租约集合。每个IA都有一个关联的IAID（见下文）。一个客户机可能分配了多个IA——例如，每个接口分配一个IA。每个IA持有一种类型的租约；例如，临时地址的标识关联（IA_TA）持有临时地址，前缀委派的标识关联（IA_PD）持有委派前缀。在本文件中，“IA”用于指身份关联，而不标识IA中的租赁类型。在编写本文档时，定义了三种IA类型：IA_NA、IA_TA和IA_PD。将来可能会定义新的IA类型。
IA option(s) At the time of writing this document, one or more IA_NA, IA_TA, and/or IA_PD options. New IA types may be defined in the future.
IA选项在编写本文件时，一个或多个IA_NA、IA_TA和/或IA_PD选项。将来可能会定义新的IA类型。
IAID Identity Association Identifier: an identifier for an IA, chosen by the client. Each IA has an IAID, which is chosen to be unique among IAIDs for IAs of a specific type that belong to that client.
IAID标识关联标识符：由客户端选择的IA标识符。每个IA都有一个IAID，该IAID在属于该客户机的特定类型的IAs的IAID中是唯一的。
IA_NA Identity Association for Non-temporary Addresses: an IA that carries assigned addresses that are not temporary addresses (see "IA_TA"). See Section 21.4 for details on the IA_NA option.
非临时地址的IA_NA标识关联：承载非临时地址的分配地址的IA（参见“IA_TA”）。有关IA_NA选项的详细信息，请参见第21.4节。
IA_PD Identity Association for Prefix Delegation: an IA that carries delegated prefixes. See Section 21.21 for details on the IA_PD option.
前缀委派的IA_PD标识关联：携带委派前缀的IA。有关IA_PD选项的详细信息，请参见第21.21节。
IA_TA Identity Association for Temporary Addresses: an IA that carries temporary addresses (see [RFC4941]). See Section 21.5 for details on the IA_TA option.
临时地址的IA_TA标识关联：携带临时地址的IA（参见[RFC4941]）。有关IA_TA选项的详细信息，请参见第21.5节。
lease A contract by which the server grants the use of an address or delegated prefix to the client for a specified period of time.
租用一个合同，根据该合同，服务器将地址或委派前缀的使用权授予客户端一段指定的时间。
message A unit of data carried as the payload of a UDP datagram, exchanged among DHCP servers, relay agents, and clients.
消息作为UDP数据报的有效负载携带的数据单元，在DHCP服务器、中继代理和客户端之间交换。
Reconfigure key A key supplied to a client by a server. Used to provide security for Reconfigure messages (see Section 7.3 for the list of available message types).
重新配置密钥服务器提供给客户端的密钥。用于为重新配置消息提供安全性（有关可用消息类型的列表，请参阅第7.3节）。
relaying A DHCP relay agent relays DHCP messages between DHCP participants.
中继DHCP中继代理在DHCP参与者之间中继DHCP消息。
requesting router The router that acts as a DHCP client and is requesting prefix(es) to be assigned. This document primarily uses the term "DHCP client" or "client" when discussing the "requesting router" functionality of prefix delegation (see Section 1).
请求路由器充当DHCP客户端并请求分配前缀的路由器。在讨论前缀委派的“请求路由器”功能时，本文档主要使用术语“DHCP客户端”或“客户端”（参见第1节）。
retransmission Another attempt to send the same DHCP message by a client or server, as a result of not receiving a valid response to the previously sent messages. The retransmitted message is typically modified prior to sending, as required by the DHCP specifications. In particular, the client updates the value of the Elapsed Time option in the retransmitted message.
重新传输由于未收到对先前发送的消息的有效响应，客户端或服务器再次尝试发送相同的DHCP消息。根据DHCP规范的要求，通常在发送之前修改重新传输的消息。特别地，客户端更新重传消息中的“已用时间”选项的值。
RKAP The Reconfiguration Key Authentication Protocol (see Section 20.4).
RKAP——重新配置密钥认证协议（见第20.4节）。
singleton option An option that is allowed to appear only once as a top-level option or at any encapsulation level. Most options are singletons.
单例选项只允许作为顶级选项或在任何封装级别显示一次的选项。大多数选择都是单身。
T1 The time interval after which the client is expected to contact the server that did the assignment to extend (renew) the lifetimes of the addresses assigned (via IA_NA option(s)) and/or prefixes delegated (via IA_PD option(s)) to the client. T1 is expressed as an absolute value in messages (in seconds), is conveyed within IA containers (currently the IA_NA and IA_PD options), and is interpreted as a time interval since the packet's reception. The value stored in the T1 field in IA options is referred to as the T1 value. The actual time when the timer expires is referred to as the T1 time.
T1指客户机希望联系进行分配的服务器以延长（续订）分配给客户机的地址（通过IA_-NA选项）和/或前缀（通过IA_-PD选项）的生命周期的时间间隔。T1表示为消息的绝对值（以秒为单位），在IA容器（当前为IA_NA和IA_PD选项）中传输，并解释为自数据包接收以来的时间间隔。IA选项中T1字段中存储的值称为T1值。计时器过期的实际时间称为T1时间。
T2 The time interval after which the client is expected to contact any available server to extend (rebind) the lifetimes of the addresses assigned (via IA_NA option(s)) and/or prefixes delegated (via IA_PD option(s)) to the client. T2 is expressed as an absolute value in messages (in seconds), is conveyed within IA containers (currently the IA_NA and IA_PD options), and is interpreted as a time interval since the packet's reception. The value stored in the T2 field in IA options is referred to as the T2 value. The actual time when the timer expires is referred to as the T2 time.
T2客户机希望联系任何可用服务器以延长（重新绑定）分配给客户机的地址（通过IA_NA选项）和/或前缀（通过IA_PD选项）的生命周期的时间间隔。T2表示为消息中的绝对值（以秒为单位），在IA容器中传输（当前为IA_NA和IA_PD选项），并被解释为自数据包接收以来的时间间隔。IA options中T2字段中存储的值称为T2值。计时器过期的实际时间称为T2时间。
top-level option An option conveyed in a DHCP message directly, i.e., not encapsulated in any other option, as described in Section 9 of [RFC7227].
顶级选项直接在DHCP消息中传输的选项，即不封装在任何其他选项中，如[RFC7227]第9节所述。
transaction ID An opaque value used to match responses with replies initiated by either a client or a server.
事务ID一个不透明的值，用于将响应与客户端或服务器启动的响应进行匹配。
Clients and servers exchange DHCP messages using UDP (see [RFC768] and BCP 145 [RFC8085]). The client uses a link-local address or addresses determined through other mechanisms for transmitting and receiving DHCP messages.
客户端和服务器使用UDP交换DHCP消息（请参阅[RFC768]和BCP 145[RFC8085]）。客户端使用链路本地地址或通过其他机制确定的地址来发送和接收DHCP消息。
A DHCP client sends most messages using a reserved, link-scoped multicast destination address so that the client need not be configured with the address or addresses of DHCP servers.
DHCP客户端使用保留的、链接范围的多播目标地址发送大多数消息，这样客户端就不需要配置DHCP服务器的一个或多个地址。
To allow a DHCP client to send a message to a DHCP server that is not attached to the same link, a DHCP relay agent on the client's link will relay messages between the client and server. The operation of the relay agent is transparent to the client. The discussion of message exchanges in the remainder of this section will omit the description of the relaying of messages by relay agents.
要允许DHCP客户端向未连接到同一链路的DHCP服务器发送消息，客户端链路上的DHCP中继代理将在客户端和服务器之间中继消息。中继代理的操作对客户端是透明的。本节剩余部分中对消息交换的讨论将省略中继代理对消息中继的描述。
Once the client has determined the address of a server, it may, under some circumstances, send messages directly to the server using unicast.
一旦客户机确定了服务器的地址，在某些情况下，它可能会使用单播直接向服务器发送消息。
When a DHCP client does not need to have a DHCP server assign IP addresses or delegated prefixes to it, the client can obtain other configuration information such as a list of available DNS servers [RFC3646] or NTP servers [RFC5908] through a single message and reply exchange with a DHCP server. To obtain other configuration information, the client first sends an Information-request message to the All_DHCP_Relay_Agents_and_Servers multicast address. Servers respond with a Reply message containing the other configuration information for the client.
当DHCP客户端不需要DHCP服务器为其分配IP地址或委派前缀时，客户端可以通过单个消息和与DHCP服务器的应答交换获得其他配置信息，如可用DNS服务器[RFC3646]或NTP服务器[RFC5908]的列表。为了获得其他配置信息，客户机首先向All_DHCP_中继_代理_和_服务器多播地址发送信息请求消息。服务器响应一条回复消息，其中包含客户端的其他配置信息。
A client may also request the server to expedite address assignment and/or prefix delegation by using a two-message exchange instead of the normal four-message exchange as discussed in the next section. Expedited assignment can be requested by the client, and servers may or may not honor the request (see Sections 18.3.1 and 21.14 for more details and why servers may not honor this request). Clients may request this expedited service in environments where it is likely that there is only one server available on a link and no expectation that a second server would become available, or when completing the configuration process as quickly as possible is a priority.
客户机还可以通过使用两条消息交换而不是下一节讨论的正常四条消息交换来请求服务器加快地址分配和/或前缀委派。客户可以请求快速分配，服务器可能会也可能不会接受该请求（有关更多详细信息以及服务器可能不会接受该请求的原因，请参阅第18.3.1节和第21.14节）。在链路上可能只有一台服务器可用且不期望第二台服务器可用的环境中，或者在优先考虑尽快完成配置过程时，客户端可能会请求此快速服务。
To request the expedited two-message exchange, the client sends a Solicit message to the All_DHCP_Relay_Agents_and_Servers multicast address requesting the assignment of addresses and/or delegated prefixes and other configuration information. This message includes an indication (the Rapid Commit option; see Section 21.14) that the client is willing to accept an immediate Reply message from the server. The server that is willing to commit the assignment of addresses and/or delegated prefixes to the client immediately responds with a Reply message. The configuration information and the addresses and/or delegated prefixes in the Reply message are then immediately available for use by the client.
为了请求加速的两个消息交换，客户端向所有\u DHCP\u中继\u代理\u和\u服务器多播地址发送请求消息，请求分配地址和/或委派前缀以及其他配置信息。此消息包括一个指示（快速提交选项；参见第21.14节），表明客户端愿意接受来自服务器的即时回复消息。愿意向客户机提交地址分配和/或委派前缀的服务器立即响应一条回复消息。然后，回复消息中的配置信息、地址和/或委派前缀立即可供客户端使用。
Each address or delegated prefix assigned to the client has associated preferred and valid lifetimes specified by the server. To request an extension of the lifetimes assigned to an address or delegated prefix, the client sends a Renew message to the server. The server sends a Reply message to the client with the new lifetimes, allowing the client to continue to use the address or delegated prefix without interruption. If the server is unable to extend the lifetime of an address or delegated prefix, it indicates this by returning the address or delegated prefix with lifetimes of 0. At the same time, the server may assign other addresses or delegated prefixes.
分配给客户端的每个地址或委派前缀都有服务器指定的相关首选和有效生存期。要请求延长分配给地址或委派前缀的生存期，客户端将向服务器发送续订消息。服务器向客户机发送一条具有新生存期的回复消息，允许客户机继续使用地址或委派前缀，而不会中断。如果服务器无法延长地址或委派前缀的生存期，它将通过返回生存期为0的地址或委派前缀来表示。同时，服务器可以分配其他地址或委派的前缀。
See Section 18 for descriptions of additional two-message exchanges between the client and server.
有关客户端和服务器之间另外两次消息交换的说明，请参见第18节。
To request the assignment of one or more addresses and/or delegated prefixes, a client first locates a DHCP server and then requests the assignment of addresses and/or delegated prefixes and other configuration information from the server. The client sends a Solicit message to the All_DHCP_Relay_Agents_and_Servers multicast address to find available DHCP servers. Any server that can meet the client's requirements responds with an Advertise message. The client then chooses one of the servers and sends a Request message to the server asking for confirmed assignment of addresses and/or delegated prefixes and other configuration information. The server responds with a Reply message that contains the confirmed addresses, delegated prefixes, and configuration.
要请求分配一个或多个地址和/或委派前缀，客户端首先查找DHCP服务器，然后从服务器请求分配地址和/或委派前缀以及其他配置信息。客户端向所有\u DHCP\u中继\u代理\u和\u服务器多播地址发送请求消息，以查找可用的DHCP服务器。任何能够满足客户机要求的服务器都会以播发消息进行响应。然后，客户机选择其中一台服务器，并向服务器发送请求消息，请求确认地址分配和/或授权前缀以及其他配置信息。服务器用一条回复消息进行响应，该消息包含已确认的地址、委派的前缀和配置。
As described in the previous section, the client can request an extension of the lifetimes assigned to addresses or delegated prefixes (this is a two-message exchange).
如前一节所述，客户机可以请求延长分配给地址或委派前缀的生命周期（这是一个两条消息交换）。
A server that has previously communicated with a client and negotiated for the client to listen for Reconfigure messages may send the client a Reconfigure message to initiate the client to update its configuration by sending an Information-request, Renew, or Rebind message. The client then performs the two-message exchange as described earlier. This can be used to expedite configuration changes to a client, such as the need to renumber a network (see [RFC6879]).
先前与客户机通信并协商让客户机监听重新配置消息的服务器可以向客户机发送重新配置消息，以通过发送信息请求、续订或重新绑定消息来启动客户机更新其配置。然后，客户机执行前面描述的两条消息交换。这可用于加快对客户机的配置更改，例如需要对网络重新编号（请参见[RFC6879]）。
This section describes some of the current most common DHCP operational models. The described models are not mutually exclusive and are sometimes used together. For example, a device may start in stateful mode to obtain an address and, at a later time when an application is started, request additional parameters using stateless mode.
本节介绍一些当前最常见的DHCP操作模型。所描述的模型并不相互排斥，有时会一起使用。例如，设备可以在有状态模式下启动以获取地址，并且在稍后启动应用程序时，可以使用无状态模式请求附加参数。
This document assumes that the DHCP servers and the client, communicating with the servers via a specific interface, belong to a single provisioning domain.
本文档假定通过特定接口与服务器通信的DHCP服务器和客户端属于单个配置域。
DHCP may be extended to support additional stateful services that may interact with one or more of the models described below. Such interaction should be considered and documented as part of any future protocol extension.
DHCP可以扩展以支持可能与下面描述的一个或多个模型交互的附加有状态服务。此类交互应作为任何未来协议扩展的一部分予以考虑和记录。
Stateless DHCP [RFC3736] is used when DHCP is not used for obtaining a lease but a node (DHCP client) desires one or more DHCP "other configuration" parameters, such as a list of DNS recursive name servers or DNS domain search lists [RFC3646]. Stateless DHCP may be used when a node initially boots or at any time the software on the node requires some missing or expired configuration information that is available via DHCP.
当DHCP不用于获取租约，但节点（DHCP客户端）需要一个或多个DHCP“其他配置”参数，如DNS递归名称服务器列表或DNS域搜索列表[RFC3646]时，使用无状态DHCP[RFC3736]。无状态DHCP可在节点初始引导时使用，或在节点上的软件需要通过DHCP提供的某些丢失或过期的配置信息时使用。
This is the simplest and most basic operation for DHCP and requires a client (and a server) to support only two messages -- Information-request and Reply. Note that DHCP servers and relay agents typically also need to support the Relay-forward and Relay-reply messages to accommodate operation when clients and servers are not on the same link.
这是DHCP最简单、最基本的操作，要求客户端（和服务器）只支持两条消息——信息请求和回复。请注意，DHCP服务器和中继代理通常还需要支持中继转发和中继回复消息，以适应客户端和服务器不在同一链路上时的操作。
This model of operation was the original motivation for DHCP. It is appropriate for situations where stateless address autoconfiguration alone is insufficient or impractical, e.g., because of network policy, additional requirements such as dynamic updates to the DNS, or client-specific requirements.
这种操作模式是DHCP最初的动机。它适用于仅无状态地址自动配置不充分或不实用的情况，例如，由于网络策略、DNS动态更新等附加要求或特定于客户端的要求。
The model of operation for non-temporary address assignment is as follows. The server is provided with prefixes from which it may allocate addresses to clients, as well as any related network topology information as to which prefixes are present on which links. A client requests a non-temporary address to be assigned by the server. The server allocates an address or addresses appropriate for the link on which the client is connected. The server returns the allocated address or addresses to the client.
非临时地址分配的操作模型如下所示。服务器提供了前缀，它可以从这些前缀向客户端分配地址，以及任何相关的网络拓扑信息，以确定哪些前缀出现在哪些链路上。客户端请求由服务器分配的非临时地址。服务器为连接客户端的链接分配一个或多个合适的地址。服务器将分配的一个或多个地址返回给客户端。
Each address has associated preferred and valid lifetimes, which constitute an agreement about the length of time over which the client is allowed to use the address. A client can request an extension of the lifetimes on an address and is required to terminate the use of an address if the valid lifetime of the address expires.
每个地址都有相关的首选和有效生存期，这构成了一个关于允许客户使用该地址的时间长度的协议。客户机可以请求延长地址的生存期，如果地址的有效生存期到期，客户机需要终止地址的使用。
Typically, clients request other configuration parameters, such as the DNS name server addresses and domain search lists, when requesting addresses.
通常，客户端在请求地址时请求其他配置参数，例如DNS名称服务器地址和域搜索列表。
Clients can also request more than one address or set of addresses (see Sections 6.6 and 12).
客户还可以请求多个地址或一组地址（参见第6.6节和第12节）。
The prefix delegation mechanism, originally described in [RFC3633], is another stateful mode of operation and was originally intended for simple delegation of prefixes from a delegating router (DHCP server) to requesting routers (DHCP clients). It is appropriate for situations in which the delegating router (1) does not have knowledge about the topology of the networks to which the requesting router is attached and (2) does not require other information aside from the identity of the requesting router to choose a prefix for delegation. This mechanism is appropriate for use by an ISP to delegate a prefix to a subscriber, where the delegated prefix would possibly be subnetted and assigned to the links within the subscriber's network. [RFC7084] and [RFC7368] describe such use in detail.
[RFC3633]中最初描述的前缀委派机制是另一种有状态操作模式，最初用于将前缀从委派路由器（DHCP服务器）简单委派给请求路由器（DHCP客户端）。它适用于授权路由器（1）不知道请求路由器所连接到的网络的拓扑，并且（2）不需要除了请求路由器的身份之外的其他信息来选择用于授权的前缀的情况。此机制适用于ISP将前缀委派给订阅者，其中委派的前缀可能会被子网化并分配给订阅者网络内的链路。[RFC7084]和[RFC7368]详细描述了此类用途。
The design of this prefix delegation mechanism meets the requirements for prefix delegation in [RFC3769].
该前缀委托机制的设计满足[RFC3769]中对前缀委托的要求。
While [RFC3633] assumes that the DHCP client is a router (hence the use of "requesting router") and that the DHCP server is a router (hence the use of "delegating router"), DHCP prefix delegation itself does not require that the client forward IP packets not addressed to itself and thus does not require that the client (or server) be a router as defined in [RFC8200]. Also, in many cases (such as tethering or hosting virtual machines), hosts are already forwarding IP packets and thus are operating as routers as defined in [RFC8200]. Therefore, this document mostly replaces "requesting router" with "client" and "delegating router" with "server".
虽然[RFC3633]假设DHCP客户端是路由器（因此使用“请求路由器”），DHCP服务器是路由器（因此使用“委托路由器”），但DHCP前缀委托本身并不要求客户端转发未寻址到自身的IP数据包，因此也不要求客户端（或服务器）转发IP数据包是[RFC8200]中定义的路由器。此外，在许多情况下（如栓系或托管虚拟机），主机已经在转发IP数据包，因此作为[RFC8200]中定义的路由器运行。因此，本文档主要将“请求路由器”替换为“客户端”，将“委托路由器”替换为“服务器”。
The model of operation for prefix delegation is as follows. A server is provisioned with prefixes to be delegated to clients. A client requests prefix(es) from the server, as described in Section 18. The server chooses prefix(es) for delegation and responds with prefix(es) to the client. The client is then responsible for the delegated prefix(es). For example, the client might assign a subnet from a delegated prefix to one of its interfaces and begin sending Router Advertisements for the prefix on that link.
前缀委派的操作模型如下所示。服务器配置了要委派给客户端的前缀。客户端从服务器请求前缀，如第18节所述。服务器为委托选择前缀，并用前缀响应客户端。然后，客户机负责委托前缀。例如，客户端可能会将一个子网从委派的前缀分配给它的一个接口，并开始在该链路上发送前缀的路由器公告。
Each prefix has an associated preferred lifetime and valid lifetime, which constitute an agreement about the length of time over which the client is allowed to use the prefix. A client can request an extension of the lifetimes on a delegated prefix and is required to terminate the use of a delegated prefix if the valid lifetime of the prefix expires.
每个前缀都有一个相关的首选生存期和有效生存期，这构成了一个关于允许客户端使用前缀的时间长度的协议。客户机可以请求延长委托前缀的生存期，如果前缀的有效生存期到期，则需要终止委托前缀的使用。
Figure 1 illustrates a network architecture in which prefix delegation could be used.
图1说明了一种可以使用前缀委派的网络体系结构。
______________________ \
/ \ \
| ISP core network | \
\__________ ___________/ |
| |
+-------+-------+ |
| Aggregation | | ISP
| device | | network
| (delegating | |
| router) | |
+-------+-------+ |
| /
|Network link to /
|subscriber premises /
|
+------+------+ \
| CPE | \
| (requesting | \
| router) | |
+----+---+----+ |
| | | Subscriber
---+-------------+-----+ +-----+------ | network
| | | |
+----+-----+ +-----+----+ +----+-----+ |
|Subscriber| |Subscriber| |Subscriber| /
| PC | | PC | | PC | /
+----------+ +----------+ +----------+ /
______________________ \
/ \ \
| ISP core network | \
\__________ ___________/ |
| |
+-------+-------+ |
| Aggregation | | ISP
| device | | network
| (delegating | |
| router) | |
+-------+-------+ |
| /
|Network link to /
|subscriber premises /
|
+------+------+ \
| CPE | \
| (requesting | \
| router) | |
+----+---+----+ |
| | | Subscriber
---+-------------+-----+ +-----+------ | network
| | | |
+----+-----+ +-----+----+ +----+-----+ |
|Subscriber| |Subscriber| |Subscriber| /
| PC | | PC | | PC | /
+----------+ +----------+ +----------+ /
Figure 1: Prefix Delegation Network
图1：前缀委派网络
In this example, the server (delegating router) is configured with a set of prefixes to be used for assignment to customers at the time of each customer's first connection to the ISP service. The prefix delegation process begins when the client (requesting router) requests configuration information through DHCP. The DHCP messages from the client are received by the server in the aggregation device. When the server receives the request, it selects an available prefix or prefixes for delegation to the client. The server then returns the prefix or prefixes to the client.
在此示例中，服务器（委托路由器）配置有一组前缀，用于在每个客户首次连接到ISP服务时分配给客户。当客户端（请求路由器）通过DHCP请求配置信息时，前缀委派过程开始。来自客户端的DHCP消息由聚合设备中的服务器接收。当服务器接收到请求时，它会选择一个或多个可用前缀，以便委托给客户端。然后，服务器将前缀返回给客户端。
The client subnets the delegated prefix and assigns the longer prefixes to links in the subscriber's network. In a typical scenario based on the network shown in Figure 1, the client subnets a single delegated /48 prefix into /64 prefixes and assigns one /64 prefix to each of the links in the subscriber network.
客户端将代理前缀子网化，并将较长的前缀分配给订户网络中的链路。在基于图1所示网络的典型场景中，客户端将单个委派的/48前缀子网化为/64前缀，并将一个/64前缀分配给订户网络中的每个链路。
The prefix delegation options can be used in conjunction with other DHCP options carrying other configuration information to the client.
前缀委派选项可以与其他DHCP选项结合使用，这些选项将其他配置信息传送到客户端。
The client may, in turn, provide DHCP service to nodes attached to the internal network. For example, the client may obtain the addresses of DNS and NTP servers from the ISP server and then pass that configuration information on to the subscriber hosts through a DHCP server in the client (requesting router).
客户机可以反过来向连接到内部网络的节点提供DHCP服务。例如，客户端可以从ISP服务器获得DNS和NTP服务器的地址，然后通过客户端（请求路由器）中的DHCP服务器将该配置信息传递给订户主机。
If the client uses a delegated prefix to configure addresses on interfaces on itself or other nodes behind it, the preferred and valid lifetimes of those addresses MUST be no longer than the remaining preferred and valid lifetimes, respectively, for the delegated prefix at any time. In particular, if the delegated prefix or a prefix derived from it is advertised for stateless address autoconfiguration [RFC4862], the advertised preferred and valid lifetimes MUST NOT exceed the corresponding remaining lifetimes of the delegated prefix.
如果客户端使用委派前缀在其自身或其后面的其他节点上的接口上配置地址，则这些地址的首选和有效生存期在任何时候都不得分别长于委派前缀的剩余首选和有效生存期。特别是，如果为无状态地址自动配置[RFC4862]播发委托前缀或其派生的前缀，则播发的首选和有效生存期不得超过委托前缀的相应剩余生存期。
The DHCP requirements and network architecture for Customer Edge Routers are described in [RFC7084]. This model of operation combines address assignment (see Section 6.2) and prefix delegation (see Section 6.3). In general, this model assumes that a single set of transactions between the client and server will assign or extend the client's non-temporary addresses and delegated prefixes.
[RFC7084]中描述了客户边缘路由器的DHCP要求和网络体系结构。这种操作模式结合了地址分配（见第6.2节）和前缀委派（见第6.3节）。通常，此模型假设客户端和服务器之间的一组事务将分配或扩展客户端的非临时地址和委派前缀。
Temporary addresses were originally introduced to avoid privacy concerns with stateless address autoconfiguration, which based 64 bits of the address on the EUI-64 (see [RFC4941]. They were added to DHCP to provide complementary support when stateful address assignment is used.
临时地址最初是为了避免无状态地址自动配置的隐私问题而引入的，该配置基于EUI-64上的64位地址（请参见[RFC4941]）。它们被添加到DHCP中，以在使用有状态地址分配时提供补充支持。
Temporary address assignment works mostly like non-temporary address assignment (see Section 6.2); however, these addresses are generally intended to be used for a short period of time and not to have their lifetimes extended, though they can be if required.
临时地址分配工作主要与非临时地址分配类似（见第6.2节）；然而，这些地址通常用于较短的时间段，不会延长其使用寿命，但如果需要，也可以这样做。
DHCP allows a client to receive multiple addresses. During typical operation, a client sends one instance of an IA_NA option and the server assigns at most one address from each prefix assigned to the link to which the client is attached. In particular, the server can be configured to serve addresses out of multiple prefixes for a given
DHCP允许客户端接收多个地址。在典型操作期间，客户端发送一个IA_NA选项实例，服务器从分配给客户端连接到的链接的每个前缀中最多分配一个地址。特别是，可以将服务器配置为在给定地址的多个前缀中提供地址
link. This is useful in cases such as when a network renumbering event is in progress. In a typical deployment, the server will grant one address for each IA_NA option (see Section 21.4).
链接这在网络重新编号事件正在进行等情况下非常有用。在典型部署中，服务器将为每个IA_NA选项授予一个地址（参见第21.4节）。
A client can explicitly request multiple addresses by sending multiple IA_NA options (and/or IA_TA options; see Section 21.5). A client can send multiple IA_NA (and/or IA_TA) options in its initial transmissions. Alternatively, it can send an extra Request message with additional new IA_NA (and/or IA_TA) options (or include them in a Renew message).
客户端可以通过发送多个IA_NA选项（和/或IA_TA选项；见第21.5节）明确请求多个地址。客户端可以在其初始传输中发送多个IA_NA（和/或IA_TA）选项。或者，它可以发送额外的请求消息，其中包含额外的新IA_NA（和/或IA_TA）选项（或将其包含在续订消息中）。
The same principle also applies to prefix delegation. In principle, DHCP allows a client to request new prefixes to be delegated by sending additional IA_PD options (see Section 21.21). However, a typical operator usually prefers to delegate a single, larger prefix. In most deployments, it is recommended that the client request a larger prefix in its initial transmissions rather than request additional prefixes later on.
同样的原则也适用于前缀授权。原则上，DHCP允许客户端通过发送额外的IA_PD选项来请求委派新前缀（参见第21.21节）。然而，一个典型的操作员通常更喜欢委派一个较大的前缀。在大多数部署中，建议客户端在其初始传输中请求更大的前缀，而不是稍后请求额外的前缀。
The exact behavior of the server (whether to grant additional addresses and prefixes or not) is up to the server policy and is out of scope for this document.
服务器的确切行为（是否授予其他地址和前缀）取决于服务器策略，不在本文档的范围内。
For more information on how the server distinguishes between IA option instances, see Section 12.
有关服务器如何区分IA选项实例的更多信息，请参阅第12节。
This section describes various program and networking constants used by DHCP.
本节介绍DHCP使用的各种程序和网络常量。
DHCP makes use of the following multicast addresses:
DHCP使用以下多播地址：
All_DHCP_Relay_Agents_and_Servers (ff02::1:2) A link-scoped multicast address used by a client to communicate with neighboring (i.e., on-link) relay agents and servers. All servers and relay agents are members of this multicast group.
所有_DHCP_中继_代理_和_服务器（ff02:：1:2）客户端用于与相邻（即链路上）中继代理和服务器通信的链路范围的多播地址。所有服务器和中继代理都是此多播组的成员。
All_DHCP_Servers (ff05::1:3) A site-scoped multicast address used by a relay agent to communicate with servers, either because the relay agent wants to send messages to all servers or because it does not know the unicast addresses of the servers. Note that in order for a relay agent to use this address, it must have an address of sufficient
All_DHCP_Servers（ff05:：1:3）中继代理用于与服务器通信的站点范围的多播地址，这可能是因为中继代理希望向所有服务器发送消息，也可能是因为它不知道服务器的单播地址。请注意，为了使中继代理使用此地址，它必须具有足够的
scope to be reachable by the servers. All servers within the site are members of this multicast group on the interfaces that are within the site.
服务器可访问的范围。站点内的所有服务器都是站点内接口上此多播组的成员。
Clients listen for DHCP messages on UDP port 546. Servers and relay agents listen for DHCP messages on UDP port 547.
客户端在UDP端口546上侦听DHCP消息。服务器和中继代理在UDP端口547上侦听DHCP消息。
DHCP defines the following message types. The formats of these messages are provided in Sections 8 and 9. Additional message types have been defined and may be defined in the future; see <https://www.iana.org/assignments/dhcpv6-parameters>. The numeric encoding for each message type is shown in parentheses.
DHCP定义了以下消息类型。第8节和第9节提供了这些信息的格式。已定义并可能在将来定义其他消息类型；看<https://www.iana.org/assignments/dhcpv6-parameters>. 括号中显示了每种消息类型的数字编码。
SOLICIT (1) A client sends a Solicit message to locate servers.
请求（1）客户端发送请求消息以定位服务器。
ADVERTISE (2) A server sends an Advertise message to indicate that it is available for DHCP service, in response to a Solicit message received from a client.
播发（2）服务器发送播发消息以指示它可用于DHCP服务，以响应从客户端接收的请求消息。
REQUEST (3) A client sends a Request message to request configuration parameters, including addresses and/or delegated prefixes, from a specific server.
请求（3）客户端从特定服务器向请求配置参数（包括地址和/或委派前缀）发送请求消息。
CONFIRM (4) A client sends a Confirm message to any available server to determine whether the addresses it was assigned are still appropriate to the link to which the client is connected.
确认（4）客户端向任何可用的服务器发送确认消息，以确定分配给它的地址是否仍然适用于客户端所连接的链接。
RENEW (5) A client sends a Renew message to the server that originally provided the client's leases and configuration parameters to extend the lifetimes on the leases assigned to the client and to update other configuration parameters.
续订（5）客户机向最初提供客户机租约和配置参数的服务器发送续订消息，以延长分配给客户机的租约的生存期并更新其他配置参数。
REBIND (6) A client sends a Rebind message to any available server to extend the lifetimes on the leases assigned to the client and to update other configuration parameters; this message is sent after a client receives no response to a Renew message.
重新绑定（6）客户端向任何可用服务器发送重新绑定消息，以延长分配给该客户端的租约的生存期，并更新其他配置参数；此消息在客户端未收到对续订消息的响应后发送。
REPLY (7) A server sends a Reply message containing assigned leases and configuration parameters in response to a Solicit, Request, Renew, or Rebind message received from a client. A server sends a Reply message containing configuration parameters in response to an Information-request message. A server sends a Reply message in response to a Confirm message confirming or denying that the addresses assigned to the client are appropriate to the link to which the client is connected. A server sends a Reply message to acknowledge receipt of a Release or Decline message.
回复（7）服务器发送包含分配的租约和配置参数的回复消息，以响应从客户端接收的请求、请求、续订或重新绑定消息。服务器发送包含配置参数的回复消息以响应信息请求消息。服务器发送回复消息以响应确认消息，确认或拒绝分配给客户机的地址适合于客户机所连接的链接。服务器发送回复消息以确认已收到释放或拒绝消息。
RELEASE (8) A client sends a Release message to the server that assigned leases to the client to indicate that the client will no longer use one or more of the assigned leases.
释放（8）客户端向向向客户端分配租约的服务器发送释放消息，以指示客户端将不再使用一个或多个分配的租约。
DECLINE (9) A client sends a Decline message to a server to indicate that the client has determined that one or more addresses assigned by the server are already in use on the link to which the client is connected.
拒绝（9）客户端向服务器发送拒绝消息，以指示客户端已确定服务器分配的一个或多个地址已在客户端所连接的链路上使用。
RECONFIGURE (10) A server sends a Reconfigure message to a client to inform the client that the server has new or updated configuration parameters and that the client is to initiate a Renew/Reply, Rebind/Reply, or Information-request/Reply transaction with the server in order to receive the updated information.
重新配置（10）服务器向客户端发送重新配置消息，以通知客户端服务器具有新的或更新的配置参数，并且客户端将与服务器发起续订/回复、重新绑定/回复或信息请求/回复事务，以接收更新的信息。
INFORMATION-REQUEST (11) A client sends an Information-request message to a server to request configuration parameters without the assignment of any leases to the client.
信息请求（11）客户端向服务器发送信息请求消息以请求配置参数，而无需向客户端分配任何租约。
RELAY-FORW (12) A relay agent sends a Relay-forward message to relay messages to servers, either directly or through another relay agent. The received message -- either a client message or a Relay-forward message from another relay agent -- is encapsulated in an option in the Relay-forward message.
中继转发（12）中继代理直接或通过另一个中继代理向服务器发送中继转发消息。接收到的消息（客户端消息或来自另一个中继代理的中继转发消息）封装在中继转发消息中的一个选项中。
RELAY-REPL (13) A server sends a Relay-reply message to a relay agent containing a message that the relay agent delivers to a client. The Relay-reply message may be relayed by other relay agents for delivery to the destination relay agent.
中继回复（13）服务器向中继代理发送中继回复消息，其中包含中继代理向客户端发送的消息。中继应答消息可以由其他中继代理中继以传送到目的地中继代理。
The server encapsulates the client message as an option in the Relay-reply message, which the relay agent extracts and relays to the client.
服务器将客户机消息封装为中继回复消息中的一个选项，中继代理提取该消息并将其中继到客户机。
DHCP makes extensive use of options in messages; some of these are defined later, in Section 21. Additional options are defined in other documents or may be defined in the future (see [RFC7227] for guidance on new option definitions).
DHCP在消息中广泛使用选项；其中一些在后面的第21节中定义。其他选项在其他文件中定义，或可能在将来定义（有关新选项定义的指南，请参见[RFC7227]）。
DHCP uses status codes to communicate the success or failure of operations requested in messages from clients and servers and to provide additional information about the specific cause of the failure of a message. The specific status codes are defined in Section 21.13.
DHCP使用状态代码传达来自客户端和服务器的消息中请求的操作的成功或失败，并提供有关消息失败的特定原因的附加信息。具体状态代码在第21.13节中定义。
If the Status Code option (see Section 21.13) does not appear in a message in which the option could appear, the status of the message is assumed to be Success.
如果状态代码选项（见第21.13节）未出现在该选项可能出现的消息中，则假定该消息的状态为成功。
This section presents a table of values used to describe the message transmission behavior of clients and servers. Some of the values are adjusted by a randomization factor and backoffs (see Section 15). Transmissions may also be influenced by rate limiting (see Section 14.1).
本节提供了一个用于描述客户端和服务器的消息传输行为的值表。一些值通过随机化因子和退避进行调整（见第15节）。传输也可能受到速率限制的影响（见第14.1节）。
+-----------------+------------------+------------------------------+
| Parameter | Default | Description |
+-----------------+------------------+------------------------------+
| SOL_MAX_DELAY | 1 sec | Max delay of first Solicit |
| | | |
| SOL_TIMEOUT | 1 sec | Initial Solicit timeout |
| | | |
| SOL_MAX_RT | 3600 secs | Max Solicit timeout value |
| | | |
| REQ_TIMEOUT | 1 sec | Initial Request timeout |
| | | |
| REQ_MAX_RT | 30 secs | Max Request timeout value |
| | | |
| REQ_MAX_RC | 10 | Max Request retry attempts |
| | | |
| CNF_MAX_DELAY | 1 sec | Max delay of first Confirm |
| | | |
| CNF_TIMEOUT | 1 sec | Initial Confirm timeout |
| | | |
| CNF_MAX_RT | 4 secs | Max Confirm timeout |
| | | |
| CNF_MAX_RD | 10 secs | Max Confirm duration |
| | | |
| REN_TIMEOUT | 10 secs | Initial Renew timeout |
| | | |
| REN_MAX_RT | 600 secs | Max Renew timeout value |
| | | |
| REB_TIMEOUT | 10 secs | Initial Rebind timeout |
| | | |
| REB_MAX_RT | 600 secs | Max Rebind timeout value |
| | | |
| INF_MAX_DELAY | 1 sec | Max delay of first |
| | | Information-request |
| | | |
| INF_TIMEOUT | 1 sec | Initial Information-request |
| | | timeout |
| | | |
| INF_MAX_RT | 3600 secs | Max Information-request |
| | | timeout value |
| | | |
+-----------------+------------------+------------------------------+
| Parameter | Default | Description |
+-----------------+------------------+------------------------------+
| SOL_MAX_DELAY | 1 sec | Max delay of first Solicit |
| | | |
| SOL_TIMEOUT | 1 sec | Initial Solicit timeout |
| | | |
| SOL_MAX_RT | 3600 secs | Max Solicit timeout value |
| | | |
| REQ_TIMEOUT | 1 sec | Initial Request timeout |
| | | |
| REQ_MAX_RT | 30 secs | Max Request timeout value |
| | | |
| REQ_MAX_RC | 10 | Max Request retry attempts |
| | | |
| CNF_MAX_DELAY | 1 sec | Max delay of first Confirm |
| | | |
| CNF_TIMEOUT | 1 sec | Initial Confirm timeout |
| | | |
| CNF_MAX_RT | 4 secs | Max Confirm timeout |
| | | |
| CNF_MAX_RD | 10 secs | Max Confirm duration |
| | | |
| REN_TIMEOUT | 10 secs | Initial Renew timeout |
| | | |
| REN_MAX_RT | 600 secs | Max Renew timeout value |
| | | |
| REB_TIMEOUT | 10 secs | Initial Rebind timeout |
| | | |
| REB_MAX_RT | 600 secs | Max Rebind timeout value |
| | | |
| INF_MAX_DELAY | 1 sec | Max delay of first |
| | | Information-request |
| | | |
| INF_TIMEOUT | 1 sec | Initial Information-request |
| | | timeout |
| | | |
| INF_MAX_RT | 3600 secs | Max Information-request |
| | | timeout value |
| | | |
| REL_TIMEOUT | 1 sec | Initial Release timeout |
| | | |
| REL_MAX_RC | 4 | Max Release retry attempts |
| | | |
| DEC_TIMEOUT | 1 sec | Initial Decline timeout |
| | | |
| DEC_MAX_RC | 4 | Max Decline retry attempts |
| | | |
| REC_TIMEOUT | 2 secs | Initial Reconfigure timeout |
| | | |
| REC_MAX_RC | 8 | Max Reconfigure attempts |
| | | |
| HOP_COUNT_LIMIT | 8 | Max hop count in a |
| | | Relay-forward message |
| | | |
| IRT_DEFAULT | 86400 secs (24 | Default information refresh |
| | hours) | time |
| | | |
| IRT_MINIMUM | 600 secs | Min information refresh time |
| | | |
| MAX_WAIT_TIME | 60 secs | Max required time to wait |
| | | for a response |
+-----------------+------------------+------------------------------+
| REL_TIMEOUT | 1 sec | Initial Release timeout |
| | | |
| REL_MAX_RC | 4 | Max Release retry attempts |
| | | |
| DEC_TIMEOUT | 1 sec | Initial Decline timeout |
| | | |
| DEC_MAX_RC | 4 | Max Decline retry attempts |
| | | |
| REC_TIMEOUT | 2 secs | Initial Reconfigure timeout |
| | | |
| REC_MAX_RC | 8 | Max Reconfigure attempts |
| | | |
| HOP_COUNT_LIMIT | 8 | Max hop count in a |
| | | Relay-forward message |
| | | |
| IRT_DEFAULT | 86400 secs (24 | Default information refresh |
| | hours) | time |
| | | |
| IRT_MINIMUM | 600 secs | Min information refresh time |
| | | |
| MAX_WAIT_TIME | 60 secs | Max required time to wait |
| | | for a response |
+-----------------+------------------+------------------------------+
Table 1: Transmission and Retransmission Parameters
表1：传输和重传参数
All time values for lifetimes, T1, and T2 are unsigned 32-bit integers and are expressed in units of seconds. The value 0xffffffff is taken to mean "infinity" when used as a lifetime (as in [RFC4861]) or a value for T1 or T2.
生命周期、T1和T2的所有时间值均为无符号32位整数，并以秒为单位表示。当用作生存期（如[RFC4861]中所述）或T1或T2的值时，值0xFFFFFF表示“无穷大”。
Setting the valid lifetime of an address or a delegated prefix to 0xffffffff ("infinity") amounts to a permanent assignment of an address or delegation to a client and should only be used in cases where permanent assignments are desired.
将地址或委托前缀的有效生存期设置为0xffffffff（“无限”）相当于将地址或委托永久分配给客户机，并且仅应在需要永久分配的情况下使用。
Care should be taken in setting T1 or T2 to 0xffffffff ("infinity"). A client will never attempt to extend the lifetimes of any addresses in an IA with T1 set to 0xffffffff. A client will never attempt to use a Rebind message to locate a different server to extend the lifetimes of any addresses in an IA with T2 set to 0xffffffff.
在将T1或T2设置为0xffffffff（“无穷大”）时应小心。在T1设置为0xFFFFFF的IA中，客户端永远不会尝试延长任何地址的生存期。在T2设置为0xFFFFFF的IA中，客户端永远不会尝试使用重新绑定消息来定位不同的服务器，以延长任何地址的生存期。
All DHCP messages sent between clients and servers share an identical fixed-format header and a variable-format area for options.
客户端和服务器之间发送的所有DHCP消息共享相同的固定格式标头和用于选项的可变格式区域。
All values in the message header and in options are in network byte order.
消息头和选项中的所有值均按网络字节顺序排列。
Options are stored serially in the "options" field, with no padding between the options. Options are byte-aligned but are not aligned in any other way (such as on 2-byte or 4-byte boundaries).
选项串行存储在“选项”字段中，选项之间没有填充。选项是字节对齐的，但不以任何其他方式对齐（例如在2字节或4字节边界上）。
The following diagram illustrates the format of DHCP messages sent between clients and servers:
下图说明了在客户端和服务器之间发送的DHCP消息的格式：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | transaction-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. options .
. (variable number and length) .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | transaction-id |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. options .
. (variable number and length) .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Client/Server Message Format
图2：客户机/服务器消息格式
msg-type Identifies the DHCP message type; the available message types are listed in Section 7.3. A 1-octet field.
msg type标识DHCP消息类型；第7.3节列出了可用的消息类型。一个1-octet字段。
transaction-id The transaction ID for this message exchange. A 3-octet field.
事务id此消息交换的事务id。三个八位组的字段。
options Options carried in this message; options are described in Section 21. A variable-length field (4 octets less than the size of the message).
此消息中包含的选项；选项在第21节中描述。可变长度字段（比消息大小小4个八位字节）。
Relay agents exchange messages with other relay agents and servers to relay messages between clients and servers that are not connected to the same link.
中继代理与其他中继代理和服务器交换消息，以在未连接到同一链路的客户端和服务器之间中继消息。
All values in the message header and in options are in network byte order.
消息头和选项中的所有值均按网络字节顺序排列。
Options are stored serially in the "options" field, with no padding between the options. Options are byte-aligned but are not aligned in any other way (such as on 2-byte or 4-byte boundaries).
选项串行存储在“选项”字段中，选项之间没有填充。选项是字节对齐的，但不以任何其他方式对齐（例如在2字节或4字节边界上）。
There are two relay agent messages (Relay-forward and Relay-reply), which share the following format:
有两条中继代理消息（中继转发和中继回复），它们共享以下格式：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | hop-count | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| link-address |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| peer-address |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. .
. options (variable number and length) .... .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type | hop-count | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| link-address |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| peer-address |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. .
. options (variable number and length) .... .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Relay Agent/Server Message Format
图3：中继代理/服务器消息格式
The following sections describe the use of the relay agent message header.
以下各节介绍中继代理消息头的使用。
The following table defines the use of message fields in a Relay-forward message.
下表定义了中继转发消息中消息字段的使用。
msg-type RELAY-FORW (12). A 1-octet field.
msg型继电器-FORW（12）。一个1-octet字段。
hop-count Number of relay agents that have already relayed this message. A 1-octet field.
跃点计数已中继此消息的中继代理数。一个1-octet字段。
link-address An address that may be used by the server to identify the link on which the client is located. This is typically a globally scoped unicast address (i.e., GUA or ULA), but see the discussion in Section 19.1.1. A 16-octet field.
链接地址服务器可用于标识客户端所在链接的地址。这通常是一个全局范围的单播地址（即GUA或ULA），但请参见第19.1.1节中的讨论。16个八位组的字段。
peer-address The address of the client or relay agent from which the message to be relayed was received. A 16-octet field.
对等地址从中接收要中继的消息的客户端或中继代理的地址。16个八位组的字段。
options MUST include a Relay Message option (see Section 21.10); MAY include other options, such as the Interface-Id option (see Section 21.18), added by the relay agent. A variable-length field (34 octets less than the size of the message).
选项必须包括中继消息选项（见第21.10节）；可能包括中继代理添加的其他选项，如接口Id选项（见第21.18节）。可变长度字段（比消息大小小34个八位字节）。
See Section 13.1 for an explanation of how the link-address field is used.
有关如何使用链接地址字段的说明，请参见第13.1节。
The following table defines the use of message fields in a Relay-reply message.
下表定义了中继回复消息中消息字段的使用。
msg-type RELAY-REPL (13). A 1-octet field.
msg型继电器-REPL（13）。一个1-octet字段。
hop-count Copied from the Relay-forward message. A 1-octet field.
从中继转发消息复制的跃点计数。一个1-octet字段。
link-address Copied from the Relay-forward message. A 16-octet field.
从中继转发消息复制的链接地址。16个八位组的字段。
peer-address Copied from the Relay-forward message. A 16-octet field.
从中继转发消息复制的对等地址。16个八位组的字段。
options MUST include a Relay Message option (see Section 21.10); MAY include other options, such as the Interface-Id option (see Section 21.18). A variable-length field (34 octets less than the size of the message).
选项必须包括中继消息选项（见第21.10节）；可能包括其他选项，如接口Id选项（见第21.18节）。可变长度字段（比消息大小小34个八位字节）。
So that domain names may be encoded uniformly, a domain name or a list of domain names is encoded using the technique described in Section 3.1 of [RFC1035]. A domain name, or list of domain names, in DHCP MUST NOT be stored in compressed form as described in Section 4.1.4 of [RFC1035].
为了对域名进行统一编码，使用[RFC1035]第3.1节中描述的技术对域名或域名列表进行编码。DHCP中的域名或域名列表不得以[RFC1035]第4.1.4节所述的压缩形式存储。
Each DHCP client and server has a DUID. DHCP servers use DUIDs to identify clients for the selection of configuration parameters and in the association of IAs with clients. DHCP clients use DUIDs to identify a server in messages where a server needs to be identified. See Sections 21.2 and 21.3 for details regarding the representation of a DUID in a DHCP message.
每个DHCP客户端和服务器都有一个DUID。DHCP服务器使用DUID识别用于选择配置参数和IAs与客户端关联的客户端。DHCP客户端使用DUID在需要标识服务器的消息中标识服务器。有关DHCP消息中DUID表示的详细信息，请参见第21.2节和第21.3节。
Clients and servers MUST treat DUIDs as opaque values and MUST only compare DUIDs for equality. Clients and servers SHOULD NOT in any other way interpret DUIDs. Clients and servers MUST NOT restrict DUIDs to the types defined in this document, as additional DUID types may be defined in the future. It should be noted that an attempt to parse a DUID to obtain a client's link-layer address is unreliable, as there is no guarantee that the client is still using the same link-layer address as when it generated its DUID. Also, such an attempt will be more and more unreliable as more clients adopt privacy measures such as those defined in [RFC7844]. If this capability is required, it is recommended to rely on the Client Link-Layer Address option instead [RFC6939].
客户端和服务器必须将DUID视为不透明值，并且必须仅比较DUID是否相等。客户端和服务器不应以任何其他方式解释DUID。客户端和服务器不得将DUID限制为本文档中定义的类型，因为将来可能会定义其他DUID类型。应该注意的是，试图解析DUID以获取客户端的链路层地址是不可靠的，因为无法保证客户端仍然使用与生成其DUID时相同的链路层地址。此外，随着越来越多的客户端采用[RFC7844]中定义的隐私措施，这种尝试将越来越不可靠。如果需要此功能，建议改用客户机链路层地址选项[RFC6939]。
The DUID is carried in an option because it may be variable in length and because it is not required in all DHCP messages. The DUID is designed to be unique across all DHCP clients and servers, and stable for any specific client or server. That is, the DUID used by a client or server SHOULD NOT change over time if at all possible; for example, a device's DUID should not change as a result of a change in the device's network hardware or changes to virtual interfaces (e.g.,
DUID包含在选项中，因为它的长度可能是可变的，并且并非所有DHCP消息都需要它。DUID在所有DHCP客户端和服务器上都是唯一的，对于任何特定的客户端或服务器都是稳定的。也就是说，如果可能的话，客户端或服务器使用的DUID不应该随时间而改变；例如，设备的DUID不应因设备网络硬件的更改或虚拟接口的更改而更改（例如。，
logical PPP (over Ethernet) interfaces that may come and go in Customer Premises Equipment routers). The client may change its DUID as specified in [RFC7844].
逻辑PPP（通过以太网）接口，可在客户场所设备路由器中进出。客户可以按照[RFC7844]中的规定更改其DUID。
The motivation for having more than one type of DUID is that the DUID must be globally unique and must also be easy to generate. The sort of globally unique identifier that is easy to generate for any given device can differ quite widely. Also, some devices may not contain any persistent storage. Retaining a generated DUID in such a device is not possible, so the DUID scheme must accommodate such devices.
拥有多种类型的DUID的动机是DUID必须是全局唯一的，并且必须易于生成。对于任何给定的设备，易于生成的全局唯一标识符的种类可能相差很大。此外，某些设备可能不包含任何持久性存储。在这样的设备中保留生成的DUID是不可能的，因此DUID方案必须适应这样的设备。
A DUID consists of a 2-octet type code represented in network byte order, followed by a variable number of octets that make up the actual identifier. The length of the DUID (not including the type code) is at least 1 octet and at most 128 octets. The following types are currently defined:
DUID由以网络字节顺序表示的2个八位字节类型的代码组成，后跟组成实际标识符的可变八位字节数。DUID的长度（不包括类型代码）至少为1个八位字节，最多为128个八位字节。目前定义了以下类型：
+------+------------------------------------------------------+
| Type | Description |
+------+------------------------------------------------------+
| 1 | Link-layer address plus time |
| 2 | Vendor-assigned unique ID based on Enterprise Number |
| 3 | Link-layer address |
| 4 | Universally Unique Identifier (UUID) [RFC6355] |
+------+------------------------------------------------------+
+------+------------------------------------------------------+
| Type | Description |
+------+------------------------------------------------------+
| 1 | Link-layer address plus time |
| 2 | Vendor-assigned unique ID based on Enterprise Number |
| 3 | Link-layer address |
| 4 | Universally Unique Identifier (UUID) [RFC6355] |
+------+------------------------------------------------------+
Table 2: DUID Types
表2：DUID类型
Formats for the variable field of the DUID for the first three of the above types are shown below. The fourth type, DUID-UUID [RFC6355], can be used in situations where there is a UUID stored in a device's firmware settings.
上述前三种类型的DUID变量字段格式如下所示。第四种类型DUID-UUID[RFC6355]可用于设备固件设置中存储UUID的情况。
This type of DUID consists of a 2-octet type field containing the value 1, a 2-octet hardware type code, and 4 octets containing a time value, followed by the link-layer address of any one network interface that is connected to the DHCP device at the time that the DUID is generated. The time value is the time that the DUID is generated, represented in seconds since midnight (UTC), January 1, 2000, modulo 2^32. The hardware type MUST be a valid hardware type assigned by IANA; see [IANA-HARDWARE-TYPES]. Both the time and the hardware type are stored in network byte order. For Ethernet hardware types, the link-layer address is stored in canonical form, as described in [RFC2464].
这种类型的DUID由包含值1的2个八位字节类型字段、2个八位字节硬件类型代码和包含时间值的4个八位字节组成，后跟生成DUID时连接到DHCP设备的任何一个网络接口的链路层地址。时间值是生成DUID的时间，表示为自2000年1月1日午夜（UTC）以来的秒数，模为2^32。硬件类型必须是IANA分配的有效硬件类型；请参阅[IANA-HARDWARE-TYPES]。时间和硬件类型都以网络字节顺序存储。对于以太网硬件类型，链路层地址以规范形式存储，如[RFC2464]所述。
The following diagram illustrates the format of a DUID-LLT:
下图说明了DUID-LLT的格式：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (1) | hardware type (16 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. link-layer address (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (1) | hardware type (16 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time (32 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. link-layer address (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: DUID-LLT Format
图4:DUID-LLT格式
The choice of network interface can be completely arbitrary, as long as that interface provides a globally unique link-layer address for the link type; the same DUID-LLT SHOULD be used in configuring all network interfaces connected to the device, regardless of which interface's link-layer address was used to generate the DUID-LLT.
网络接口的选择可以完全任意，只要该接口为链路类型提供全局唯一的链路层地址；在配置连接到设备的所有网络接口时，应使用相同的DUID-LLT，无论使用哪个接口的链路层地址生成DUID-LLT。
Clients and servers using this type of DUID MUST store the DUID-LLT in stable storage and MUST continue to use this DUID-LLT even if the network interface used to generate the DUID-LLT is removed. Clients and servers that do not have any stable storage MUST NOT use this type of DUID.
使用此类型DUID的客户端和服务器必须将DUID-LLT存储在稳定的存储中，并且即使删除了用于生成DUID-LLT的网络接口，也必须继续使用此DUID-LLT。没有任何稳定存储的客户端和服务器不得使用此类DUID。
Clients and servers that use this DUID SHOULD attempt to configure the time prior to generating the DUID, if that is possible, and MUST use some sort of time source (for example, a real-time clock) in generating the DUID, even if that time source could not be configured prior to generating the DUID. The use of a time source makes it unlikely that two identical DUID-LLTs will be generated if the network interface is removed from the client and another client then uses the same network interface to generate a DUID-LLT. A collision between two DUID-LLTs is very unlikely even if the clocks have not been configured prior to generating the DUID.
如果可能，使用此DUID的客户端和服务器应尝试在生成DUID之前配置时间，并且在生成DUID时必须使用某种时间源（例如，实时时钟），即使在生成DUID之前无法配置该时间源。如果从客户端移除网络接口，并且另一个客户端使用相同的网络接口生成DUID-LLT，则使用时间源不太可能生成两个相同的DUID LLT。即使在生成DUID之前未配置时钟，两个DUID LLT之间的冲突也不太可能发生。
This method of DUID generation is recommended for all general-purpose computing devices such as desktop computers and laptop computers, and also for devices such as printers, routers, and so on, that contain some form of writable non-volatile storage.
这种DUID生成方法推荐用于所有通用计算设备，如台式计算机和笔记本电脑，以及包含某种形式的可写非易失性存储的设备，如打印机、路由器等。
It is possible that this algorithm for generating a DUID could result in a client identifier collision. A DHCP client that generates a DUID-LLT using this mechanism MUST provide an administrative interface that replaces the existing DUID with a newly generated DUID-LLT.
此生成DUID的算法可能会导致客户端标识符冲突。使用此机制生成DUID-LLT的DHCP客户端必须提供一个管理接口，用新生成的DUID-LLT替换现有的DUID。
The vendor assigns this form of DUID to the device. This DUID consists of the 4-octet vendor's registered Private Enterprise Number as maintained by IANA [IANA-PEN] followed by a unique identifier assigned by the vendor. The following diagram summarizes the structure of a DUID-EN:
供应商将此形式的DUID分配给设备。该DUID由IANA[IANA-PEN]维护的4-octet供应商的注册私营企业编号组成，后跟供应商分配的唯一标识符。下图总结了DUID-EN的结构：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (2) | enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number (contd) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. identifier .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (2) | enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number (contd) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. identifier .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: DUID-EN Format
图5:DUID-EN格式
The source of the identifier is left up to the vendor defining it, but each identifier part of each DUID-EN MUST be unique to the device that is using it, and MUST be assigned to the device no later than at the first usage and stored in some form of non-volatile storage. This typically means being assigned during the manufacturing process in the case of physical devices or, in the case of virtual machines, when the image is created or booted for the first time. The generated DUID SHOULD be recorded in non-erasable storage. The enterprise-number is the vendor's registered Private Enterprise Number as maintained by IANA [IANA-PEN]. The enterprise-number is stored as an unsigned 32-bit number.
标识符的来源由定义它的供应商决定，但每个DUID-EN的每个标识符部分必须对使用它的设备是唯一的，并且必须不迟于第一次使用时分配给设备，并存储在某种形式的非易失性存储中。对于物理设备，这通常意味着在制造过程中进行分配，对于虚拟机，则意味着在首次创建或启动映像时进行分配。生成的DUID应记录在不可擦除存储器中。企业编号是供应商注册的私营企业编号，由IANA[IANA-PEN]维护。企业编号存储为无符号32位数字。
An example DUID of this type might look like this:
此类型的示例DUID可能如下所示：
+---+---+---+---+---+---+---+---+
| 0 | 2 | 0 | 0 | 0 | 9| 12|192|
+---+---+---+---+---+---+---+---+
|132|211| 3 | 0 | 9 | 18|
+---+---+---+---+---+---+
+---+---+---+---+---+---+---+---+
| 0 | 2 | 0 | 0 | 0 | 9| 12|192|
+---+---+---+---+---+---+---+---+
|132|211| 3 | 0 | 9 | 18|
+---+---+---+---+---+---+
Figure 6: DUID-EN Example
图6:DUID-EN示例
This example includes the 2-octet type of 2 and the Enterprise Number (9), followed by 8 octets of identifier data (0x0CC084D303000912).
此示例包括2个八位字节类型2和企业编号（9），后跟8个八位字节的标识符数据（0x0CC084D303000912）。
This type of DUID consists of 2 octets containing a DUID type of 3 and a 2-octet network hardware type code, followed by the link-layer address of any one network interface that is permanently connected to the client or server device. For example, a node that has a network interface implemented in a chip that is unlikely to be removed and used elsewhere could use a DUID-LL. The hardware type MUST be a valid hardware type assigned by IANA; see [IANA-HARDWARE-TYPES]. The hardware type is stored in network byte order. The link-layer address is stored in canonical form, as described in [RFC2464]. The following diagram illustrates the format of a DUID-LL:
这种类型的DUID由2个八位字节组成，其中包含DUID类型3和2个八位字节的网络硬件类型代码，后跟永久连接到客户端或服务器设备的任何一个网络接口的链路层地址。例如，在芯片中实现网络接口的节点不太可能被移除并在其他地方使用，可以使用DUID-LL。硬件类型必须是IANA分配的有效硬件类型；请参阅[IANA-HARDWARE-TYPES]。硬件类型以网络字节顺序存储。链路层地址以规范形式存储，如[RFC2464]所述。下图说明了DUID-LL的格式：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (3) | hardware type (16 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. link-layer address (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (3) | hardware type (16 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. link-layer address (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: DUID-LL Format
图7:DUID-LL格式
The choice of network interface can be completely arbitrary, as long as that interface provides a unique link-layer address and is permanently attached to the device on which the DUID-LL is being generated. The same DUID-LL SHOULD be used in configuring all network interfaces connected to the device, regardless of which interface's link-layer address was used to generate the DUID.
网络接口的选择可以是完全任意的，只要该接口提供唯一的链路层地址并永久连接到正在生成DUID-LL的设备。在配置连接到设备的所有网络接口时，应使用相同的DUID-LL，无论使用哪个接口的链路层地址生成DUID。
A DUID-LL is recommended for devices that have a permanently connected network interface with a link-layer address and do not have nonvolatile, writable stable storage. A DUID-LL SHOULD NOT be used by DHCP clients or servers that cannot tell whether or not a network interface is permanently attached to the device on which the DHCP client is running.
DUID-LL建议用于具有永久连接的网络接口和链路层地址且没有非易失性、可写稳定存储器的设备。无法判断网络接口是否永久连接到运行DHCP客户端的设备的DHCP客户端或服务器不应使用DUID-LL。
This type of DUID consists of 16 octets containing a 128-bit UUID. [RFC6355] details when to use this type and how to pick an appropriate source of the UUID.
这种类型的DUID由16个包含128位UUID的八位字节组成。[RFC6355]详细说明何时使用此类型以及如何选择适当的UUID源。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (4) | UUID (128 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| |
| -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DUID-Type (4) | UUID (128 bits) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| |
| -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Figure 8: DUID-UUID Format
图8:DUID-UUID格式
An Identity Association (IA) is a construct through which a server and a client can identify, group, and manage a set of related IPv6 addresses or delegated prefixes. Each IA consists of an IAID and associated configuration information.
身份关联（IA）是一种结构，通过它，服务器和客户端可以识别、分组和管理一组相关的IPv6地址或委派前缀。每个IA由一个IAID和相关的配置信息组成。
The IAID uniquely identifies the IA and MUST be chosen to be unique among the IAIDs for that IA type on the client (e.g., an IA_NA with an IAID of 0 and an IA_PD with an IAID of 0 are each considered unique). The IAID is chosen by the client. For any given use of an IA by the client, the IAID for that IA MUST be consistent across restarts of the DHCP client. The client may maintain consistency by either storing the IAID in non-volatile storage or using an algorithm that will consistently produce the same IAID as long as the configuration of the client has not changed. There may be no way for a client to maintain consistency of the IAIDs if it does not have non-volatile storage and the client's hardware configuration changes. If the client uses only one IAID, it can use a well-known value, e.g., zero.
IAID唯一地标识IA，并且必须选择为在客户端上该IA类型的IAID中唯一（例如，IAID为0的IA_-NA和IAID为0的IA_-PD都被认为是唯一的）。IAID由客户端选择。对于客户端对IA的任何给定使用，该IA的IAID必须在DHCP客户端重新启动时保持一致。客户机可以通过将IAID存储在非易失性存储器中或使用算法来保持一致性，只要客户机的配置没有改变，该算法将始终如一地产生相同的IAID。如果客户端没有非易失性存储，并且客户端的硬件配置发生更改，则客户端可能无法保持IAID的一致性。如果客户端仅使用一个IAID，则可以使用已知值，例如零。
If the client wishes to obtain a distinctly new address or prefix and deprecate the existing one, the client sends a Release message to the server for the IAs using the original IAID. The client then creates a new IAID, to be used in future messages to obtain leases for the new IA.
如果客户端希望获得一个全新的地址或前缀，并拒绝使用现有地址或前缀，则客户端将使用原始IAID向服务器发送IAs的释放消息。然后，客户端创建一个新的IAID，用于将来的消息中，以获取新IA的租约。
A client must associate at least one distinct IA with each of its network interfaces for which it is to request the assignment of IPv6 addresses from a DHCP server. The client uses the IAs assigned to an interface to obtain configuration information from a server for that interface. Each such IA must be associated with exactly one interface.
客户端必须将至少一个不同的IA与其每个网络接口相关联，以便从DHCP服务器请求分配IPv6地址。客户端使用分配给接口的IAs从服务器获取该接口的配置信息。每个这样的IA必须仅与一个接口关联。
The configuration information in an IA_NA option consists of one or more IPv6 addresses along with the T1 and T2 values for the IA. See Section 21.4 for details regarding the representation of an IA_NA in a DHCP message.
IA_NA选项中的配置信息包括一个或多个IPv6地址以及IA的T1和T2值。有关DHCP消息中IA_NA表示的详细信息，请参见第21.4节。
The configuration information in an IA_TA option consists of one or more IPv6 addresses. See Section 21.5 for details regarding the representation of an IA_TA in a DHCP message.
IA_TA选项中的配置信息由一个或多个IPv6地址组成。有关DHCP消息中IA_TA表示的详细信息，请参见第21.5节。
Each address in an IA has a preferred lifetime and a valid lifetime, as defined in [RFC4862]. The lifetimes are transmitted from the DHCP server to the client in the IA Address option (see Section 21.6). The lifetimes apply to the use of addresses; see Section 5.5.4 of [RFC4862].
IA中的每个地址都有一个首选生存期和一个有效生存期，如[RFC4862]中所定义。生命周期通过IA地址选项从DHCP服务器传输到客户端（见第21.6节）。有效期适用于地址的使用；参见[RFC4862]第5.5.4节。
An IA_PD is different from an IA for address assignment in that it does not need to be associated with exactly one interface. One IA_PD can be associated with the client, with a set of interfaces, or with exactly one interface. A client configured to request delegated prefixes must create at least one distinct IA_PD. It may associate a distinct IA_PD with each of its downstream network interfaces and use that IA_PD to obtain a prefix for that interface from the server.
IA_PD与IA for address assignment的不同之处在于，它不需要仅与一个接口关联。一个IA_PD可以与客户端、一组接口或仅一个接口相关联。配置为请求委派前缀的客户端必须至少创建一个不同的IA_PD。它可以将不同的IA_PD与其每个下游网络接口相关联，并使用该IA_PD从服务器获取该接口的前缀。
The configuration information in an IA_PD option consists of one or more prefixes along with the T1 and T2 values for the IA_PD. See Section 21.21 for details regarding the representation of an IA_PD in a DHCP message.
IA_PD选项中的配置信息包括一个或多个前缀以及IA_PD的T1和T2值。有关DHCP消息中IA_PD表示的详细信息，请参见第21.21节。
Each delegated prefix in an IA has a preferred lifetime and a valid lifetime, as defined in [RFC4862]. The lifetimes are transmitted from the DHCP server to the client in the IA Prefix option (see Section 21.22). The lifetimes apply to the use of delegated prefixes; see Section 5.5.4 of [RFC4862].
IA中的每个委派前缀都有一个首选生存期和一个有效生存期，如[RFC4862]中所定义。生命周期通过IA前缀选项从DHCP服务器传输到客户端（参见第21.22节）。生命周期适用于委托前缀的使用；参见[RFC4862]第5.5.4节。
A server selects addresses to be assigned to an IA_NA according to the address assignment policies determined by the server administrator and the specific information the server determines about the client from some combination of the following sources:
服务器根据服务器管理员确定的地址分配策略以及服务器从以下来源的某些组合中确定的有关客户端的特定信息，选择要分配给IA_NA的地址：
- The link to which the client is attached. The server determines the link as follows:
- 客户端连接到的链接。服务器按如下方式确定链接：
* If the server receives the message directly from the client and the source address in the IP datagram in which the message was received is a link-local address, then the client is on the same link to which the interface over which the message was received is attached.
* 如果服务器直接从客户机接收消息，并且接收消息的IP数据报中的源地址是链路本地地址，则客户机位于连接接收消息的接口的同一链路上。
* If the server receives the message from a forwarding relay agent, then the client is on the same link as the one to which the interface, identified by the link-address field in the message from the relay agent, is attached. According to [RFC6221], the server MUST ignore any link-address field whose value is zero. The link-address in this case may come from any of the Relay-forward messages encapsulated in the received Relay-forward, and in general the most encapsulated (closest Relay-forward to the client) has the most useful value.
* 如果服务器从转发中继代理接收到消息，则客户端位于与接口连接的链路相同的链路上，该接口由来自中继代理的消息中的链路地址字段标识。根据[RFC6221]，服务器必须忽略任何值为零的链接地址字段。在这种情况下，链路地址可能来自封装在接收到的中继转发中的任何中继转发消息，并且通常封装最紧密的（距离客户端最近的中继转发）具有最有用的值。
* If the server receives the message directly from the client and the source address in the IP datagram in which the message was received is not a link-local address, then the client is on the link identified by the source address in the IP datagram (note that this situation can occur only if the server has enabled the use of unicast message delivery by the client and the client has sent a message for which unicast delivery is allowed).
* 如果服务器直接从客户端接收消息，并且接收消息的IP数据报中的源地址不是链路本地地址，则客户端位于由IP数据报中的源地址标识的链路上（请注意，只有当服务器已启用客户端使用单播消息传递，并且客户端已发送允许单播传递的消息时，才会发生这种情况）。
- The DUID supplied by the client.
- 客户端提供的DUID。
- Other information in options supplied by the client, e.g., IA Address options (see Section 21.6) that include the client's requests for specific addresses.
- 客户提供的选项中的其他信息，例如IA地址选项（见第21.6节），包括客户对特定地址的请求。
- Other information in options supplied by the relay agent.
- 中继代理提供的选项中的其他信息。
By default, DHCP server implementations SHOULD NOT generate predictable addresses (see Section 4.7 of [RFC7721]). Server implementers are encouraged to review [RFC4941], [RFC7824], and [RFC7707] as to possible considerations for how to generate addresses.
默认情况下，DHCP服务器实现不应生成可预测的地址（请参阅[RFC7721]第4.7节）。鼓励服务器实现者查看[RFC4941]、[RFC7824]和[RFC7707]中关于如何生成地址的可能注意事项。
A server MUST NOT assign an address that is otherwise reserved for some other purpose. For example, a server MUST NOT assign addresses that use a reserved IPv6 Interface Identifier [RFC5453] [RFC7136] [IANA-RESERVED-IID].
服务器不得分配为其他目的保留的地址。例如，服务器不得分配使用保留IPv6接口标识符[RFC5453][RFC7136][IANA-REFERED-IID]的地址。
See [RFC7969] for a more detailed discussion on how servers determine a client's location on the network.
有关服务器如何确定客户端在网络上的位置的更详细讨论，请参阅[RFC7969]。
A client may request the assignment of temporary addresses (see [RFC4941] for the definition of temporary addresses). DHCP handling of address assignment is no different for temporary addresses.
客户可以请求分配临时地址（有关临时地址的定义，请参见[RFC4941]）。对于临时地址，地址分配的DHCP处理没有什么不同。
Clients ask for temporary addresses, and servers assign them. Temporary addresses are carried in the IA_TA option (see Section 21.5). Each IA_TA option typically contains at least one temporary address for each of the prefixes on the link to which the client is attached.
客户端请求临时地址，服务器分配它们。临时地址包含在IA_TA选项中（见第21.5节）。每个IA_TA选项通常至少包含一个用于连接客户端的链接上每个前缀的临时地址。
The lifetime of the assigned temporary address is set in the IA Address option (see Section 21.6) encapsulated in the IA_TA option. It is RECOMMENDED to set short lifetimes, typically shorter than TEMP_VALID_LIFETIME and TEMP_PREFERRED_LIFETIME (see Section 5 of [RFC4941]).
分配的临时地址的生存期在IA地址选项（见第21.6节）中设置，该选项封装在IA_TA选项中。建议设置较短的寿命，通常短于临时有效寿命和临时首选寿命（见[RFC4941]第5节）。
A DHCP server implementation MAY generate temporary addresses, referring to the algorithm defined in Section 3.2.1 of [RFC4941], with the additional condition that any new address is not the same as any assigned address.
DHCP服务器实现可参考[RFC4941]第3.2.1节中定义的算法生成临时地址，附加条件是任何新地址与任何分配的地址不同。
The server MAY update the DNS for a temporary address, as described in Section 4 of [RFC4941].
如[RFC4941]第4节所述，服务器可更新临时地址的DNS。
On the clients, by default, temporary addresses are preferred in source address selection, according to Rule 7 in Section 5 of [RFC6724]. However, this policy can be overridden.
在客户机上，根据[RFC6724]第5节中的规则7，默认情况下，在源地址选择中首选临时地址。但是，此策略可以被覆盖。
One of the most important properties of a temporary address is to make it difficult to link the address to different actions over time. So, it is NOT RECOMMENDED for a client to renew temporary addresses, though DHCP provides for such a possibility (see Section 21.5).
临时地址最重要的特性之一是，随着时间的推移，很难将地址链接到不同的操作。因此，不建议客户端更新临时地址，尽管DHCP提供了这种可能性（参见第21.5节）。
The mechanism through which the server selects prefix(es) for delegation is not specified in this document. Examples of ways in which the server might select prefix(es) for a client include static assignment based on subscription to an ISP, dynamic assignment from a pool of available prefixes, and selection based on an external authority such as a RADIUS server using the Framed-IPv6-Prefix option as described in [RFC3162].
本文档中未指定服务器为委派选择前缀的机制。服务器可能为客户端选择前缀的方式示例包括基于对ISP的订阅的静态分配、来自可用前缀池的动态分配，以及基于外部机构（例如使用Framed-IPv6-prefix选项的RADIUS服务器）的选择，如[RFC3162]中所述。
Unless otherwise specified in this document or in a document that describes how IPv6 is carried over a specific type of link (for link types that do not support multicast), a client sends DHCP messages to the All_DHCP_Relay_Agents_and_Servers multicast address.
除非本文档或描述如何通过特定类型的链路（对于不支持多播的链路类型）承载IPv6的文档中另有规定，否则客户端将向所有\u DHCP\u中继\u代理\u和\u服务器多播地址发送DHCP消息。
DHCP servers SHOULD NOT check to see whether the Layer 2 address used was multicast or not, as long as the Layer 3 address was correct.
DHCP服务器不应检查使用的第2层地址是否为多播地址，只要第3层地址正确。
A client uses multicast to reach all servers or an individual server. An individual server is indicated by specifying that server's DUID in a Server Identifier option (see Section 21.3) in the client's message. (All servers will receive this message, but only the indicated server will respond.) All servers are indicated when this option is not supplied.
客户端使用多播访问所有服务器或单个服务器。通过在客户端消息中的服务器标识符选项（参见第21.3节）中指定服务器的DUID来指示单个服务器。（所有服务器都将收到此消息，但只有指定的服务器才会响应。）未提供此选项时，将指示所有服务器。
A client may send some messages directly to a server using unicast, as described in Section 21.12.
如第21.12节所述，客户端可以使用单播直接向服务器发送一些消息。
In order to avoid prolonged message bursts that may be caused by possible logic loops, a DHCP client MUST limit the rate of DHCP messages it transmits or retransmits. One example is that a client obtains an address or delegated prefix but does not like the response, so it reverts back to the Solicit procedure, discovers the same (sole) server, requests an address or delegated prefix, and gets the same address or delegated prefix as before (as the server has
为了避免可能的逻辑循环导致长时间的消息突发，DHCP客户端必须限制其传输或重新传输DHCP消息的速率。一个示例是，客户机获得地址或委派前缀，但不喜欢响应，因此它返回到请求过程，发现同一（唯一）服务器，请求地址或委派前缀，并获得与以前相同的地址或委派前缀（如服务器所具有）
this previously requested lease assigned to this client). This loop can repeat infinitely if there is not a quit/stop mechanism. Therefore, a client must not initiate transmissions too frequently.
此先前请求的租约已分配给此客户）。如果没有退出/停止机制，该循环可以无限重复。因此，客户端不能太频繁地发起传输。
A recommended method for implementing the rate-limiting function is a token bucket (see Appendix A of [RFC3290]), limiting the average rate of transmission to a certain number in a certain time interval. This method of bounding burstiness also guarantees that the long-term transmission rate will not be exceeded.
实现速率限制功能的推荐方法是令牌桶（参见[RFC3290]的附录A），将平均传输速率限制为特定时间间隔内的特定数字。这种限制突发性的方法还保证不会超过长期传输速率。
A transmission rate limit SHOULD be configurable. A possible default could be 20 packets in 20 seconds.
传输速率限制应该是可配置的。可能的默认值是20秒内20个数据包。
For a device that has multiple interfaces, the limit MUST be enforced on a per-interface basis.
对于具有多个接口的设备，必须基于每个接口实施限制。
Rate limiting of forwarded DHCP messages and server-side messages is out of scope for this specification.
转发的DHCP消息和服务器端消息的速率限制超出本规范的范围。
In certain cases, T1 and/or T2 values may be set to 0. Currently, there are three such cases:
在某些情况下，T1和/或T2值可设置为0。目前，此类案件有三起：
1. a client received an IA_NA option (see Section 21.4) with a zero value
1. 客户收到的IA_NA选项（见第21.4节）为零值
2. a client received an IA_PD option (see Section 21.21) with a zero value
2. 客户收到的IA_PD选项（见第21.21节）为零值
3. a client received an IA_TA option (see Section 21.5) (which does not contain T1 and T2 fields and these leases are not generally renewed)
3. 客户收到IA_TA期权（见第21.5节）（不包含T1和T2字段，且这些租赁通常不续签）
This is an indication that the renew and rebind times are left to the discretion of the client. However, they are not completely discretionary.
这表明续订和重新绑定时间由客户自行决定。然而，它们并不是完全自由裁量的。
When T1 and/or T2 values are set to 0, the client MUST choose a time to avoid packet storms. In particular, it MUST NOT transmit immediately. If the client received multiple IA options, it SHOULD pick renew and/or rebind transmission times so all IA options are handled in one exchange, if possible. The client MUST choose renew and rebind times to not violate rate-limiting restrictions as defined in Section 14.1.
当T1和/或T2值设置为0时，客户端必须选择一个时间来避免数据包风暴。特别是，它不能立即传播。如果客户端收到多个IA选项，则应选择续订和/或重新绑定传输时间，以便在一次交换中处理所有IA选项（如果可能）。客户必须选择续订和重新绑定时间，以避免违反第14.1节中规定的费率限制。
DHCP clients are responsible for reliable delivery of messages in the client-initiated message exchanges described in Section 18. If a DHCP client fails to receive an expected response from a server, the client must retransmit its message according to the retransmission strategy described in this section.
DHCP客户端负责在第18节所述的客户端发起的消息交换中可靠地传递消息。如果DHCP客户端无法从服务器接收到预期的响应，则该客户端必须根据本节中描述的重传策略重传其消息。
Note that the procedure described in this section is slightly modified when used with the Solicit message. The modified procedure is described in Section 18.2.1.
请注意，当与请求消息一起使用时，本节中描述的过程略有修改。第18.2.1节描述了修改后的程序。
The client begins the message exchange by transmitting a message to the server. The message exchange terminates when either (1) the client successfully receives the appropriate response or responses from a server or servers or (2) the message exchange is considered to have failed according to the retransmission mechanism described below.
客户端通过向服务器发送消息来开始消息交换。当（1）客户端成功地从一个或多个服务器接收到适当的响应，或者（2）根据下面描述的重传机制，消息交换被认为失败时，消息交换终止。
The client MUST update an "elapsed-time" value within an Elapsed Time option (see Section 21.9) in the retransmitted message. In some cases, the client may also need to modify values in IA Address options (see Section 21.6) or IA Prefix options (see Section 21.22) if a valid lifetime for any of the client's leases expires before retransmission. Thus, whenever this document refers to a "retransmission" of a client's message, it refers to both modifying the original message and sending this new message instance to the server.
客户端必须在重新传输的消息中的已用时间选项（见第21.9节）内更新“已用时间”值。在某些情况下，如果客户的任何租约的有效期限在重新传输之前到期，则客户可能还需要修改IA地址选项（参见第21.6节）或IA前缀选项（参见第21.22节）中的值。因此，每当本文档提到客户机消息的“重新传输”时，它都指修改原始消息并将此新消息实例发送到服务器。
The client retransmission behavior is controlled and described by the following variables:
客户端重传行为由以下变量控制和描述：
RT Retransmission timeout
RT重传超时
IRT Initial retransmission time
初始重传时间
MRC Maximum retransmission count
最大重传计数
MRT Maximum retransmission time
最大重传时间
MRD Maximum retransmission duration
最大重传持续时间
RAND Randomization factor
兰德随机化因子
Specific values for each of these parameters relevant to the various messages are given in the subsections of Section 18.2, using values defined in Table 1 in Section 7.6. The algorithm for RAND is common across all message transmissions.
第18.2节小节给出了与各种信息相关的每个参数的具体值，使用第7.6节表1中定义的值。RAND算法在所有消息传输中都是通用的。
With each message transmission or retransmission, the client sets RT according to the rules given below. If RT expires before the message exchange terminates, the client recomputes RT and retransmits the message.
在每次消息传输或重传时，客户机根据下面给出的规则设置RT。如果RT在消息交换终止之前过期，客户端将重新计算RT并重新传输消息。
Each of the computations of a new RT includes a randomization factor (RAND), which is a random number chosen with a uniform distribution between -0.1 and +0.1. The randomization factor is included to minimize synchronization of messages transmitted by DHCP clients.
新RT的每次计算都包含一个随机化因子（RAND），该因子是一个随机数，其均匀分布在-0.1和+0.1之间。随机化因子用于最小化DHCP客户端传输的消息的同步。
The algorithm for choosing a random number does not need to be cryptographically sound. The algorithm SHOULD produce a different sequence of random numbers from each invocation of the DHCP client.
选择一个随机数的算法不需要在密码上可靠。该算法应该从DHCP客户端的每次调用中产生不同的随机数序列。
RT for the first message transmission is based on IRT:
第一次消息传输的RT基于IRT：
RT = IRT + RAND*IRT
RT = IRT + RAND*IRT
RT for each subsequent message transmission is based on the previous value of RT:
每个后续消息传输的RT基于之前的RT值：
RT = 2*RTprev + RAND*RTprev
RT = 2*RTprev + RAND*RTprev
MRT specifies an upper bound on the value of RT (disregarding the randomization added by the use of RAND). If MRT has a value of 0, there is no upper limit on the value of RT. Otherwise:
MRT指定RT值的上限（忽略使用RAND增加的随机化）。如果MRT的值为0，则RT的值没有上限。否则：
if (RT > MRT)
RT = MRT + RAND*MRT
if (RT > MRT)
RT = MRT + RAND*MRT
MRC specifies an upper bound on the number of times a client may retransmit a message. Unless MRC is zero, the message exchange fails once the client has transmitted the message MRC times.
MRC指定客户端可以重新传输消息的次数上限。除非MRC为零，否则一旦客户机传输消息MRC次，消息交换就会失败。
MRD specifies an upper bound on the length of time a client may retransmit a message. Unless MRD is zero, the message exchange fails once MRD seconds have elapsed since the client first transmitted the message.
MRD指定客户端可以重新传输消息的时间长度上限。除非MRD为零，否则自客户端首次传输消息以来，一旦MRD秒过去，消息交换就会失败。
If both MRC and MRD are non-zero, the message exchange fails whenever either of the conditions specified in the previous two paragraphs is met.
如果MRC和MRD均为非零，则只要满足前两段中指定的任一条件，消息交换就会失败。
If both MRC and MRD are zero, the client continues to transmit the message until it receives a response.
如果MRC和MRD都为零，则客户端将继续传输消息，直到收到响应为止。
A client is not expected to listen for a response during the entire RT period and may turn off listening capabilities after waiting at least the shorter of RT and MAX_WAIT_TIME due to power consumption saving or other reasons. Of course, a client MUST listen for a Reconfigure if it has negotiated for its use with the server.
在整个RT周期内，客户机不需要侦听响应，并且在等待至少RT和MAX_WAIT_时间中较短的一个时间后，可能会由于省电或其他原因而关闭侦听功能。当然，如果客户机已与服务器协商使用，则必须侦听重新配置。
This section describes which options are valid in which kinds of message types and explains what to do when a client or server receives a message that contains known options that are invalid for that message. For example, an IA option is not allowed to appear in an Information-request message.
本节描述了在何种类型的消息中哪些选项是有效的，并解释了当客户端或服务器接收到包含对该消息无效的已知选项的消息时该怎么办。例如，信息请求消息中不允许出现IA选项。
Clients and servers MAY choose to either (1) extract information from such a message if the information is of use to the recipient or (2) ignore such a message completely and just discard it.
客户机和服务器可以选择（1）从此类邮件中提取信息（如果信息对收件人有用），或者（2）完全忽略此类邮件并将其丢弃。
If a server receives a message that it considers invalid, it MAY send a Reply message (or Advertise message, as appropriate) with a Server Identifier option (see Section 21.3), a Client Identifier option (see Section 21.2) (if one was included in the message), and a Status Code option (see Section 21.13) with status UnspecFail.
如果服务器接收到它认为无效的消息，它可以发送带有服务器标识符选项（见第21.3节）、客户端标识符选项（见第21.2节）（如果消息中包含一个）和状态代码选项（见第21.13节）的回复消息（或播发消息，视情况而定），状态为UnspecFail。
Clients, relay agents, and servers MUST NOT discard messages that contain unknown options (or instances of vendor options with unknown enterprise-number values). These should be ignored as if they were not present. This is critical to provide for future extensions of DHCP.
客户端、中继代理和服务器不得丢弃包含未知选项（或具有未知企业编号值的供应商选项实例）的消息。这些应该被忽略，就好像它们不存在一样。这对于提供DHCP的未来扩展至关重要。
A server MUST discard any Solicit, Confirm, Rebind, or Information-request messages it receives with a Layer 3 unicast destination address.
服务器必须丢弃它使用第3层单播目标地址接收的任何请求、确认、重新绑定或信息请求消息。
A client or server MUST discard any received DHCP messages with an unknown message type.
客户端或服务器必须丢弃任何接收到的消息类型未知的DHCP消息。
The "transaction-id" field holds a value used by clients and servers to synchronize server responses to client messages. A client SHOULD generate a random number that cannot easily be guessed or predicted to use as the transaction ID for each new message it sends. Note that if a client generates easily predictable transaction identifiers, it may become more vulnerable to certain kinds of attacks from off-path intruders. A client MUST leave the transaction ID unchanged in retransmissions of a message.
“事务id”字段保存客户端和服务器用于同步服务器对客户端消息的响应的值。客户机应该生成一个随机数，该随机数不容易猜测或预测，可以用作它发送的每个新消息的事务ID。请注意，如果客户端生成易于预测的事务标识符，则它可能更容易受到来自非路径入侵者的某些类型的攻击。在重新传输消息时，客户端必须保持事务ID不变。
Clients MUST discard any received Solicit messages.
客户端必须丢弃任何收到的请求消息。
Servers MUST discard any Solicit messages that do not include a Client Identifier option or that do include a Server Identifier option.
服务器必须丢弃任何不包含客户端标识符选项或包含服务器标识符选项的请求消息。
Clients MUST discard any received Advertise message that meets any of the following conditions:
客户端必须丢弃满足以下任何条件的任何接收到的播发消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the message does not include a Client Identifier option (see Section 21.2).
- 该消息不包括客户端标识符选项（见第21.2节）。
- the contents of the Client Identifier option do not match the client's DUID.
- 客户端标识符选项的内容与客户端的DUID不匹配。
- the "transaction-id" field value does not match the value the client used in its Solicit message.
- “事务id”字段值与客户端在其请求消息中使用的值不匹配。
Servers and relay agents MUST discard any received Advertise messages.
服务器和中继代理必须丢弃任何接收到的播发消息。
Clients MUST discard any received Request messages.
客户端必须丢弃任何接收到的请求消息。
Servers MUST discard any received Request message that meets any of the following conditions:
服务器必须丢弃满足以下任何条件的任何接收到的请求消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the contents of the Server Identifier option do not match the server's DUID.
- 服务器标识符选项的内容与服务器的DUID不匹配。
- the message does not include a Client Identifier option (see Section 21.2).
- 该消息不包括客户端标识符选项（见第21.2节）。
Clients MUST discard any received Confirm messages.
客户端必须丢弃任何收到的确认消息。
Servers MUST discard any received Confirm messages that do not include a Client Identifier option (see Section 21.2) or that do include a Server Identifier option (see Section 21.3).
服务器必须丢弃任何接收到的确认消息，这些消息不包括客户端标识符选项（参见第21.2节）或包含服务器标识符选项（参见第21.3节）。
Clients MUST discard any received Renew messages.
客户端必须丢弃任何接收到的续订消息。
Servers MUST discard any received Renew message that meets any of the following conditions:
服务器必须丢弃满足以下任何条件的任何接收到的续订消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the contents of the Server Identifier option do not match the server's identifier.
- 服务器标识符选项的内容与服务器的标识符不匹配。
- the message does not include a Client Identifier option (see Section 21.2).
- 该消息不包括客户端标识符选项（见第21.2节）。
Clients MUST discard any received Rebind messages.
客户端必须丢弃任何接收到的重新绑定消息。
Servers MUST discard any received Rebind messages that do not include a Client Identifier option (see Section 21.2) or that do include a Server Identifier option (see Section 21.3).
服务器必须丢弃任何接收到的不包含客户端标识符选项（见第21.2节）或包含服务器标识符选项（见第21.3节）的重新绑定消息。
Clients MUST discard any received Decline messages.
客户端必须丢弃任何接收到的拒绝消息。
Servers MUST discard any received Decline message that meets any of the following conditions:
服务器必须丢弃满足以下任何条件的任何接收到的拒绝消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the contents of the Server Identifier option do not match the server's identifier.
- 服务器标识符选项的内容与服务器的标识符不匹配。
- the message does not include a Client Identifier option (see Section 21.2).
- 该消息不包括客户端标识符选项（见第21.2节）。
Clients MUST discard any received Release messages.
客户端必须丢弃任何接收到的发布消息。
Servers MUST discard any received Release message that meets any of the following conditions:
服务器必须丢弃满足以下任何条件的任何接收到的发布消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the contents of the Server Identifier option do not match the server's identifier.
- 服务器标识符选项的内容与服务器的标识符不匹配。
- the message does not include a Client Identifier option (see Section 21.2).
- 该消息不包括客户端标识符选项（见第21.2节）。
Clients MUST discard any received Reply message that meets any of the following conditions:
客户端必须丢弃任何满足以下任何条件的接收回复消息：
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the "transaction-id" field in the message does not match the value used in the original message.
- 消息中的“事务id”字段与原始消息中使用的值不匹配。
If the client included a Client Identifier option (see Section 21.2) in the original message, the Reply message MUST include a Client Identifier option, and the contents of the Client Identifier option MUST match the DUID of the client. If the client did not include a Client Identifier option in the original message, the Reply message MUST NOT include a Client Identifier option.
如果客户端在原始消息中包含客户端标识符选项（见第21.2节），则回复消息必须包含客户端标识符选项，并且客户端标识符选项的内容必须与客户端的DUID匹配。如果客户端未在原始消息中包含客户端标识符选项，则回复消息不得包含客户端标识符选项。
Servers and relay agents MUST discard any received Reply messages.
服务器和中继代理必须丢弃任何收到的回复消息。
Servers and relay agents MUST discard any received Reconfigure messages.
服务器和中继代理必须丢弃任何接收到的重新配置消息。
Clients MUST discard any Reconfigure message that meets any of the following conditions:
客户端必须放弃满足以下任何条件的任何重新配置消息：
- the message was not unicast to the client.
- 消息未单播到客户端。
- the message does not include a Server Identifier option (see Section 21.3).
- 该消息不包括服务器标识符选项（参见第21.3节）。
- the message does not include a Client Identifier option (see Section 21.2) that contains the client's DUID.
- 该消息不包括包含客户端DUID的客户端标识符选项（见第21.2节）。
- the message does not include a Reconfigure Message option (see Section 21.19).
- 该信息不包括重新配置信息选项（见第21.19节）。
- the Reconfigure Message option msg-type is not a valid value.
- 重新配置消息选项msg type不是有效值。
- the message does not include authentication (such as RKAP; see Section 20.4) or fails authentication validation.
- 该消息不包括身份验证（如RKAP；参见第20.4节）或身份验证失败。
Clients MUST discard any received Information-request messages.
客户端必须丢弃任何接收到的信息请求消息。
Servers MUST discard any received Information-request message that meets any of the following conditions:
服务器必须丢弃满足以下任何条件的任何接收到的信息请求消息：
- the message includes a Server Identifier option (see Section 21.3), and the DUID in the option does not match the server's DUID.
- 该消息包含一个服务器标识符选项（见第21.3节），该选项中的DUID与服务器的DUID不匹配。
- the message includes an IA option.
- 该消息包含一个IA选项。
Clients MUST discard any received Relay-forward messages.
客户端必须丢弃任何接收到的中继转发消息。
Clients and servers MUST discard any received Relay-reply messages.
客户端和服务器必须丢弃任何接收到的中继回复消息。
The client's behavior regarding interface selection is different, depending on the purpose of the configuration.
根据配置的目的，客户端在界面选择方面的行为是不同的。
When a client sends a DHCP message to the All_DHCP_Relay_Agents_and_Servers multicast address, it SHOULD send the message through the interface for which configuration information (including the addresses) is being requested. However, the client MAY send the message through another interface if the interface for which configuration is being requested is a logical interface without direct link attachment or the client is certain that two interfaces are attached to the same link.
当客户端将DHCP消息发送到所有\u DHCP\u中继\u代理\u和\u服务器多播地址时，它应通过请求配置信息（包括地址）的接口发送消息。但是，如果请求配置的接口是没有直接链接连接的逻辑接口，或者客户端确定两个接口连接到同一链接，则客户端可以通过另一个接口发送消息。
When a client sends a DHCP message directly to a server using unicast (after receiving the Server Unicast option (see Section 21.12) from that server), the source address in the header of the IPv6 datagram MUST be an address assigned to the interface for which the client is interested in obtaining configuration and that is suitable for use by the server in responding to the client.
当客户端使用单播直接向服务器发送DHCP消息时（从该服务器接收到服务器单播选项（见第21.12节）），IPv6数据报报头中的源地址必须是分配给客户端有兴趣获取配置的接口的地址，该地址适合服务器在响应客户端时使用。
Delegated prefixes are not associated with a particular interface in the same way as addresses are for address assignment as mentioned in Section 17.1 above.
委托前缀与特定接口的关联方式与上文第17.1节所述地址分配的地址不相同。
When a client sends a DHCP message for the purpose of prefix delegation, it SHOULD be sent on the interface associated with the upstream router (typically, connected to an ISP network); see [RFC7084]. The upstream interface is typically determined by configuration. This rule applies even in the case where a separate IA_PD is used for each downstream interface.
当客户端出于前缀委派的目的发送DHCP消息时，它应该在与上游路由器相关联的接口上发送（通常连接到ISP网络）；见[RFC7084]。上游接口通常由配置决定。即使在每个下游接口使用单独IA_PD的情况下，该规则也适用。
When a client sends a DHCP message directly to a server using unicast (after receiving the Server Unicast option (see Section 21.12) from that server), the source address SHOULD be an address that is from the upstream interface and that is suitable for use by the server in responding to the client.
当客户端使用单播直接向服务器发送DHCP消息时（在从该服务器接收到服务器单播选项（见第21.12节）后），源地址应该是来自上游接口的地址，并且适合服务器在响应客户端时使用。
A client initiates a message exchange with a server or servers to acquire or update configuration information of interest. A client has many reasons to initiate the configuration exchange. Some of the more common ones are:
客户端启动与一个或多个服务器的消息交换，以获取或更新感兴趣的配置信息。客户机有许多原因来启动配置交换。较常见的有：
1. as part of the operating system configuration/bootstrap process,
1. 作为操作系统配置/引导过程的一部分，
2. when requested to do so by the application layer (through an operating-system-specific API),
2. 当应用层（通过特定于操作系统的API）请求时，
3. when a Router Advertisement indicates that DHCPv6 is available for address configuration (see Section 4.2 of [RFC4861]),
3. 当路由器公告表明DHCPv6可用于地址配置时（参见[RFC4861]第4.2节），
4. as required to extend the lifetime of address(es) and/or delegated prefix(es), using Renew and Rebind messages, or
4. 根据需要使用续订和重新绑定消息延长地址和/或委派前缀的生存期，或
5. upon the receipt of a Reconfigure message, when requested to do so by a server.
5. 当服务器请求重新配置消息时，收到重新配置消息。
The client is responsible for creating IAs and requesting that a server assign addresses and/or delegated prefixes to the IAs. The client first creates the IAs and assigns IAIDs to them. The client then transmits a Solicit message containing the IA options describing the IAs. The client MUST NOT be using any of the addresses or delegated prefixes for which it tries to obtain the bindings by sending the Solicit message. In particular, if the client had some valid bindings and has chosen to start the server discovery process to obtain the same bindings from a different server, the client MUST stop using the addresses and delegated prefixes for the bindings that it had obtained from the previous server (see Section 18.2.7 for more details on what "stop using" means in this context) and that it is now trying to obtain from a new server.
客户机负责创建IAs，并请求服务器为IAs分配地址和/或委派前缀。客户端首先创建IAs并为其分配IAID。然后，客户端发送一条请求消息，其中包含描述IAs的IA选项。客户端不得使用其试图通过发送请求消息获取绑定的任何地址或委派前缀。特别是，如果客户机具有一些有效绑定，并且选择启动服务器发现过程以从不同的服务器获取相同的绑定，则客户机必须停止使用从以前的服务器获取的绑定的地址和委派前缀（有关“停止使用”的详细信息，请参阅第18.2.7节）这意味着它现在正试图从新服务器获取。
A DHCP client that does not need to have a DHCP server assign IP addresses or delegated prefixes to it can obtain configuration information such as a list of available DNS servers [RFC3646] or NTP servers [RFC5908] through a single message and reply exchange with a DHCP server. To obtain configuration information, the client first sends an Information-request message (see Section 18.2.6) to the All_DHCP_Relay_Agents_and_Servers multicast address. Servers respond with a Reply message containing the configuration information for the client (see Section 18.3.6).
不需要DHCP服务器为其分配IP地址或委派前缀的DHCP客户端可以通过单个消息和与DHCP服务器的应答交换获得配置信息，如可用DNS服务器[RFC3646]或NTP服务器[RFC5908]的列表。为了获得配置信息，客户端首先向所有\u DHCP\u中继\u代理\u和\u服务器多播地址发送信息请求消息（见第18.2.6节）。服务器通过包含客户端配置信息的回复消息进行响应（参见第18.3.6节）。
To request the assignment of one or more addresses or delegated prefixes, a client first locates a DHCP server and then requests the assignment of addresses/prefixes and other configuration information from the server. The client does this by sending the Solicit message (see Section 18.2.1) to the All_DHCP_Relay_Agents_and_Servers multicast address and collecting Advertise messages from the servers that respond to the client's message; the client then selects a server from which it wants to obtain configuration information. This process is referred to as server discovery. When the client has selected the server, it sends a Request message to that server as described in Section 18.2.2.
要请求分配一个或多个地址或委派的前缀，客户端首先查找DHCP服务器，然后从服务器请求分配地址/前缀和其他配置信息。客户端通过将请求消息（见第18.2.1节）发送到所有\u DHCP\u中继\u代理\u和\u服务器多播地址，并从响应客户端消息的服务器收集播发消息来实现此目的；然后，客户机选择要从中获取配置信息的服务器。此过程称为服务器发现。当客户机选择了服务器时，它会向该服务器发送一条请求消息，如第18.2.2节所述。
A client willing to perform the Solicit/Reply message exchange described in Section 18.2.1 includes a Rapid Commit option (see Section 21.14) in its Solicit message.
愿意执行第18.2.1节所述请求/回复消息交换的客户在其请求消息中包括快速提交选项（见第21.14节）。
Servers that can assign addresses or delegated prefixes to the IAs respond to the client with an Advertise message or Reply message if the client included a Rapid Commit option and the server is configured to accept it.
如果客户端包含快速提交选项，并且服务器配置为接受该选项，则可以向IAs分配地址或委派前缀的服务器将通过播发消息或回复消息响应客户端。
If the server responds with an Advertise message, the client initiates a configuration exchange as described in Section 18.2.2.
如果服务器响应播发消息，则客户端将启动配置交换，如第18.2.2节所述。
A server may initiate a message exchange with a client by sending a Reconfigure message to cause the client to send a Renew, Rebind, or Information-request message to refresh its configuration information as soon as the Reconfigure message is received by the client.
服务器可以通过发送重新配置消息来启动与客户机的消息交换，以使客户机在收到重新配置消息后立即发送续订、重新绑定或信息请求消息以刷新其配置信息。
Figure 9 shows a timeline diagram of the messages exchanged between a client and two servers for the typical lifecycle of one or more leases. This starts with the four-message Solicit/Advertise/ Request/Reply exchange to obtain the lease(s), followed by a two-message Renew/Reply exchange to extend the lifetime on the lease(s), and then ends with a two-message Release/Reply exchange to end the client's use of the lease(s).
图9显示了一个或多个租约的典型生命周期中客户端和两个服务器之间交换的消息的时间线图。这从四个消息请求/广告/请求/回复交换开始以获得租约，然后是两个消息续订/回复交换以延长租约的生存期，然后以两个消息释放/回复交换结束以结束客户端对租约的使用。
Server Server (not selected) Client (selected)
服务器（未选定）客户端（选定）
v v v
| | |
| Begins initialization |
| | |
start of | _____________/|\_____________ |
4-message |/ Solicit | Solicit \|
exchange | | |
Determines | Determines
configuration | configuration
| | |
|\ | ____________/|
| \________ | /Advertise |
| Advertise\ |/ |
| \ | |
| Collects Advertises |
| \ | |
| Selects configuration |
| | |
| _____________/|\_____________ |
|/ Request | Request \|
| | |
| | Commits configuration
| | |
end of | | _____________/|
4-message | |/ Reply |
exchange | | |
| Initialization complete |
| | |
. . .
. . .
| T1 (renewal) timer expires |
| | |
v v v
| | |
| Begins initialization |
| | |
start of | _____________/|\_____________ |
4-message |/ Solicit | Solicit \|
exchange | | |
Determines | Determines
configuration | configuration
| | |
|\ | ____________/|
| \________ | /Advertise |
| Advertise\ |/ |
| \ | |
| Collects Advertises |
| \ | |
| Selects configuration |
| | |
| _____________/|\_____________ |
|/ Request | Request \|
| | |
| | Commits configuration
| | |
end of | | _____________/|
4-message | |/ Reply |
exchange | | |
| Initialization complete |
| | |
. . .
. . .
| T1 (renewal) timer expires |
| | |
2-message | _____________/|\_____________ |
exchange |/ Renew | Renew \|
| | |
| | Commits extended lease(s)
| | |
| | _____________/|
| |/ Reply |
. . .
. . .
| | |
| Graceful shutdown |
| | |
2-message | _____________/|\_____________ |
exchange |/ Release | Release \|
| | |
| | Discards lease(s)
| | |
| | _____________/|
| |/ Reply |
| | |
v v v
2-message | _____________/|\_____________ |
exchange |/ Renew | Renew \|
| | |
| | Commits extended lease(s)
| | |
| | _____________/|
| |/ Reply |
. . .
. . .
| | |
| Graceful shutdown |
| | |
2-message | _____________/|\_____________ |
exchange |/ Release | Release \|
| | |
| | Discards lease(s)
| | |
| | _____________/|
| |/ Reply |
| | |
v v v
Figure 9: Timeline Diagram of the Messages Exchanged between a Client and Two Servers for the Typical Lifecycle of One or More Leases
图9：在一个或多个租约的典型生命周期中，客户端和两个服务器之间交换的消息的时间线图
This document assumes that a client SHOULD use a single transaction for all of the IA options required on an interface; this simplifies the client implementation and reduces the potential number of transactions required (for the background on this design choice, refer to Section 4 of [RFC7550]). To facilitate a client's use of a single transaction for all IA options, servers MUST return the same T1/T2 values for all IA options in a Reply (see Sections 18.3.2, 18.3.4, and 18.3.5) so that the client will generate a single transaction when renewing or rebinding its leases. However, because some servers may not yet conform to this requirement, a client MUST be prepared to select appropriate T1/T2 times as described in Section 18.2.4.
本文档假设客户应使用单个事务处理接口上所需的所有IA选项；这简化了客户端实现并减少了所需的潜在事务数（有关此设计选择的背景信息，请参阅[RFC7550]第4节）。为了方便客户对所有IA选项使用单一事务，服务器必须在回复中为所有IA选项返回相同的T1/T2值（参见第18.3.2、18.3.4和18.3.5节），以便客户在续订或重新绑定其租约时生成单一事务。但是，由于某些服务器可能还不符合此要求，客户机必须准备好选择第18.2.4节所述的适当T1/T2时间。
A client uses the Solicit message to discover DHCP servers configured to assign leases or return other configuration parameters on the link to which the client is attached.
客户端使用请求消息来发现配置为在客户端所连接的链接上分配租约或返回其他配置参数的DHCP服务器。
A client uses Request, Renew, Rebind, Release, and Decline messages during the normal lifecycle of addresses and delegated prefixes.
客户端在地址和委派前缀的正常生命周期内使用请求、续订、重新绑定、释放和拒绝消息。
When a client detects that it may have moved to a new link, it uses Confirm if it only has addresses and Rebind if it has delegated prefixes (and addresses). It uses Information-request messages when it needs configuration information but no addresses and no prefixes.
当客户端检测到它可能已移动到新链接时，它将使用“确认是否只有地址”和“重新绑定是否有委派前缀（和地址）”。当需要配置信息但没有地址和前缀时，它使用信息请求消息。
When a client requests multiple IA option types or multiple instances of the same IA types in a Solicit, Request, Renew, or Rebind, it is possible that the available server(s) may only be configured to offer a subset of them. When possible, the client SHOULD use the best configuration available and continue to request the additional IAs in subsequent messages. This allows the client to maintain a single session and state machine. In practice, especially in the case of handling IA_NA and IA_PD requests [RFC7084], this situation should be rare or a result of a temporary operational error. Thus, it is more likely that the client will get all configuration if it continues, in each subsequent configuration exchange, to request all the configuration information it is programmed to try to obtain, including any stateful configuration options for which no results were returned in previous message exchanges.
当客户端在请求、请求、续订或重新绑定中请求多个IA选项类型或相同IA类型的多个实例时，可用服务器可能仅配置为提供其中的一个子集。如果可能，客户端应使用可用的最佳配置，并在后续消息中继续请求额外的IAs。这允许客户端维护单个会话和状态机。在实践中，尤其是在处理IA_NA和IA_PD请求[RFC7084]的情况下，这种情况应该很少发生，或者是由于临时操作错误造成的。因此，如果客户机在每个后续配置交换中继续请求其编程尝试获取的所有配置信息，包括在先前的消息交换中未返回结果的任何有状态配置选项，则更有可能获得所有配置。
Upon receipt of a Reconfigure message from the server, a client responds with a Renew, Rebind, or Information-request message as indicated by the Reconfigure Message option (see Section 21.19). The client SHOULD be suspicious of the Reconfigure message (they may be faked), and it MUST NOT abandon any resources it might have already obtained. The client SHOULD treat the Reconfigure message as if the T1 timer had expired. The client will expect the server to send IAs and/or other configuration information to the client in a Reply message.
从服务器收到重新配置消息后，客户机将按照重新配置消息选项（见第21.19节）的指示，以续订、重新绑定或信息请求消息进行响应。客户端应该怀疑重新配置消息（它们可能是伪造的），并且不能放弃可能已经获得的任何资源。客户端应将重新配置消息视为T1计时器已过期。客户端希望服务器在回复消息中向客户端发送IAs和/或其他配置信息。
If the client has a source address of sufficient scope that can be used by the server as a return address and the client has received a Server Unicast option (see Section 21.12) from the server, the client SHOULD unicast any Request, Renew, Release, and Decline messages to the server.
如果客户端具有足够范围的源地址，服务器可以将其用作返回地址，并且客户端已从服务器接收到服务器单播选项（请参阅第21.12节），则客户端应将任何请求、续订、发布和拒绝消息单播到服务器。
Use of unicast may avoid delays due to the relaying of messages by relay agents, as well as avoid overhead on servers due to the delivery of client messages to multiple servers. However, requiring the client to relay all DHCP messages through a relay agent enables the inclusion of relay agent options in all messages sent by the client. The server should enable the use of unicast only when relay agent options will not be used.
使用单播可以避免由于中继代理转发消息而导致的延迟，以及避免由于将客户端消息传递到多个服务器而导致的服务器开销。但是，要求客户端通过中继代理中继所有DHCP消息可以在客户端发送的所有消息中包含中继代理选项。只有在不使用中继代理选项时，服务器才应启用单播。
The client sets the "msg-type" field to SOLICIT. The client generates a transaction ID and inserts this value in the "transaction-id" field.
客户端将“msg type”字段设置为请求。客户端生成一个事务ID并将该值插入“事务ID”字段。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server. The client includes IA options for any IAs to which it wants the server to assign leases.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。客户机包括其希望服务器向其分配租约的任何IAs的IA选项。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client uses IA_NA options (see Section 21.4) to request the assignment of non-temporary addresses, IA_TA options (see Section 21.5) to request the assignment of temporary addresses, and IA_PD options (see Section 21.21) to request prefix delegation. IA_NA, IA_TA, or IA_PD options, or a combination of all, can be included in DHCP messages. In addition, multiple instances of any IA option type can be included.
客户使用IA_-NA选项（见第21.4节）请求分配非临时地址，IA_-TA选项（见第21.5节）请求分配临时地址，IA_-PD选项（见第21.21节）请求前缀委派。DHCP消息中可以包含IA_NA、IA_TA或IA_PD选项，或所有选项的组合。此外，可以包括任何IA选项类型的多个实例。
The client MAY include addresses in IA Address options (see Section 21.6) encapsulated within IA_NA and IA_TA options as hints to the server about the addresses for which the client has a preference.
客户端可以在IA地址选项（见第21.6节）中包含地址，这些地址封装在IA_NA和IA_TA选项中，作为向服务器提示客户端首选地址的提示。
The client MAY include values in IA Prefix options (see Section 21.22) encapsulated within IA_PD options as hints for the delegated prefix and/or prefix length for which the client has a preference. See Section 18.2.4 for more on prefix-length hints.
客户可以将IA前缀选项（见第21.22节）中的值包含在IA_PD选项中，作为客户首选的委托前缀和/或前缀长度的提示。有关前缀长度提示的更多信息，请参见第18.2.4节。
The client MUST include an Option Request option (ORO) (see Section 21.7) to request the SOL_MAX_RT option (see Section 21.24) and any other options the client is interested in receiving. The client MAY additionally include instances of those options that are identified in the Option Request option, with data values as hints to the server about parameter values the client would like to have returned.
客户必须包括期权申请期权（ORO）（见第21.7节）以申请SOL_MAX_RT期权（见第21.24节）以及客户有兴趣接收的任何其他期权。客户机还可以包括在选项请求选项中标识的那些选项的实例，并将数据值作为关于客户机希望返回的参数值的提示发送给服务器。
The client includes a Reconfigure Accept option (see Section 21.20) if the client is willing to accept Reconfigure messages from the server.
如果客户机愿意接受来自服务器的重新配置消息，则客户机包括重新配置接受选项（参见第21.20节）。
The client MUST NOT include any other options in the Solicit message, except as specifically allowed in the definition of individual options.
客户不得在征求信息中包含任何其他选项，除非个别选项定义中明确允许。
The first Solicit message from the client on the interface SHOULD be delayed by a random amount of time between 0 and SOL_MAX_DELAY. This random delay helps desynchronize clients that start a DHCP session at the same time, such as after recovery from a power failure or after a router outage after seeing that DHCP is available in Router Advertisement messages (see Section 4.2 of [RFC4861]).
来自接口上客户端的第一条请求消息应延迟0到SOL_MAX_DELAY之间的随机时间量。此随机延迟有助于取消同时启动DHCP会话的客户端的同步，例如在从电源故障恢复后或在路由器广告消息中看到DHCP可用后的路由器中断后（请参阅[RFC4861]第4.2节）。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT SOL_TIMEOUT
IRT SOL_超时
MRT SOL_MAX_RT
捷运Solu\u MAX\u RT
MRC 0
MRC 0
MRD 0
MRD 0
A client that wishes to use the Rapid Commit two-message exchange includes a Rapid Commit option (see Section 21.14) in its Solicit message. The client may receive a number of different replies from different servers. The client will make note of any valid Advertise messages that it receives. The client will discard any Reply messages that do not contain the Rapid Commit option.
希望使用快速提交两条消息交换的客户机在其请求消息中包括快速提交选项（见第21.14节）。客户端可能会从不同的服务器接收大量不同的回复。客户端将记录它收到的任何有效的广告消息。客户端将丢弃任何不包含快速提交选项的回复消息。
Upon receipt of a valid Reply with the Rapid Commit option, the client processes the message as described in Section 18.2.10.
在收到带有快速提交选项的有效回复后，客户机将按照第18.2.10节所述处理消息。
At the end of the first RT period, if no suitable Reply messages are received but the client has valid Advertise messages, then the client processes the Advertise as described in Section 18.2.9.
在第一个RT周期结束时，如果没有收到合适的回复消息，但客户机有有效的播发消息，则客户机按照第18.2.9节中的说明处理播发。
If the client subsequently receives a valid Reply message that includes a Rapid Commit option, it does one of the following:
如果客户端随后收到包含快速提交选项的有效回复消息，则会执行以下操作之一：
- processes the Reply message as described in Section 18.2.10 and discards any Reply messages received in response to the Request message
- 按照第18.2.10节所述处理回复消息，并丢弃响应请求消息而收到的任何回复消息
- processes any Reply messages received in response to the Request message and discards the Reply message that includes the Rapid Commit option
- 处理响应请求消息而收到的任何回复消息，并丢弃包含快速提交选项的回复消息
If the client is waiting for an Advertise message, the mechanism described in Section 15 is modified as follows for use in the transmission of Solicit messages. The message exchange is not terminated by the receipt of an Advertise before the first RT has elapsed. Rather, the client collects valid Advertise messages until
如果客户端正在等待播发消息，则第15节中描述的机制被修改如下，以用于请求消息的传输。在第一次RT结束之前，消息交换不会因收到播发而终止。相反，客户端收集有效的广告消息，直到
the first RT has elapsed. Also, the first RT MUST be selected to be strictly greater than IRT by choosing RAND to be strictly greater than 0.
第一个RT已过。此外，通过选择RAND严格大于0，必须选择第一个RT严格大于IRT。
A client MUST collect valid Advertise messages for the first RT seconds, unless it receives a valid Advertise message with a preference value of 255. The preference value is carried in the Preference option (see Section 21.8). Any valid Advertise that does not include a Preference option is considered to have a preference value of 0. If the client receives a valid Advertise message that includes a Preference option with a preference value of 255, the client immediately begins a client-initiated message exchange (as described in Section 18.2.2) by sending a Request message to the server from which the Advertise message was received. If the client receives a valid Advertise message that does not include a Preference option with a preference value of 255, the client continues to wait until the first RT elapses. If the first RT elapses and the client has received a valid Advertise message, the client SHOULD continue with a client-initiated message exchange by sending a Request message.
客户端必须在第一个RT秒收集有效的播发消息，除非它接收到首选项值为255的有效播发消息。首选项值包含在首选项选项中（见第21.8节）。任何不包含首选项选项的有效播发都被视为首选项值为0。如果客户机收到一条有效的播发消息，其中包含一个首选项选项，首选项值为255，则客户机通过向接收播发消息的服务器发送请求消息，立即开始客户机发起的消息交换（如第18.2.2节所述）。如果客户端接收到一条有效的播发消息，该消息不包括首选项值为255的首选项选项，则客户端将继续等待，直到第一个RT过期。如果第一个RT已过，并且客户端已收到有效的播发消息，则客户端应通过发送请求消息继续进行客户端启动的消息交换。
If the client does not receive any valid Advertise messages before the first RT has elapsed, it then applies the retransmission mechanism described in Section 15. The client terminates the retransmission process as soon as it receives any valid Advertise message, and the client acts on the received Advertise message without waiting for any additional Advertise messages.
如果客户机在第一个RT过去之前没有收到任何有效的播发消息，则应用第15节中描述的重传机制。客户机在收到任何有效的播发消息后立即终止重传过程，并且客户机在不等待任何其他播发消息的情况下对收到的播发消息进行操作。
A DHCP client SHOULD choose MRC and MRD values of 0. If the DHCP client is configured with either MRC or MRD set to a value other than 0, it MUST stop trying to configure the interface if the message exchange fails. After the DHCP client stops trying to configure the interface, it SHOULD restart the reconfiguration process after some external event, such as user input, system restart, or when the client is attached to a new link.
DHCP客户端应选择MRC和MRD值0。如果配置DHCP客户端时将MRC或MRD设置为0以外的值，则在消息交换失败时，它必须停止尝试配置接口。DHCP客户端停止尝试配置接口后，应在某些外部事件（如用户输入、系统重新启动或客户端连接到新链接）后重新启动重新配置过程。
The client uses a Request message to populate IAs with leases and obtain other configuration information. The client includes one or more IA options in the Request message. The server then returns leases and other information about the IAs to the client in IA options in a Reply message.
客户机使用请求消息向IAs填充租约并获取其他配置信息。客户端在请求消息中包含一个或多个IA选项。然后，服务器将租约和有关IAs的其他信息返回到答复消息中的IA选项中的客户端。
The client sets the "msg-type" field to REQUEST. The client generates a transaction ID and inserts this value in the "transaction-id" field.
客户端将“msg type”字段设置为请求。客户端生成一个事务ID并将该值插入“事务ID”字段。
The client MUST include the identifier of the destination server in a Server Identifier option (see Section 21.3).
客户端必须在服务器标识符选项中包含目标服务器的标识符（参见第21.3节）。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server. The client adds any other appropriate options, including one or more IA options.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。客户端添加任何其他适当的选项，包括一个或多个IA选项。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client MUST include an Option Request option (see Section 21.7) to request the SOL_MAX_RT option (see Section 21.24) and any other options the client is interested in receiving. The client MAY additionally include instances of those options that are identified in the Option Request option, with data values as hints to the server about parameter values the client would like to have returned.
客户必须包括一个选项请求选项（见第21.7节）以请求SOL_MAX_RT选项（见第21.24节）以及客户有兴趣接收的任何其他选项。客户机还可以包括在选项请求选项中标识的那些选项的实例，并将数据值作为关于客户机希望返回的参数值的提示发送给服务器。
The client includes a Reconfigure Accept option (see Section 21.20) if the client is willing to accept Reconfigure messages from the server.
如果客户机愿意接受来自服务器的重新配置消息，则客户机包括重新配置接受选项（参见第21.20节）。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT REQ_TIMEOUT
请求超时
MRT REQ_MAX_RT
捷运需求最大值
MRC REQ_MAX_RC
MRC要求最大值
MRD 0
MRD 0
If the message exchange fails, the client takes an action based on the client's local policy. Examples of actions the client might take include the following:
如果消息交换失败，客户端将根据客户端的本地策略采取操作。客户端可能采取的操作示例包括：
- Select another server from a list of servers known to the client -- for example, servers that responded with an Advertise message.
- 从客户机已知的服务器列表中选择另一个服务器，例如，响应了播发消息的服务器。
- Initiate the server discovery process described in Section 18.
- 启动第18节中描述的服务器发现过程。
- Terminate the configuration process and report failure.
- 终止配置过程并报告故障。
The client uses a Confirm message when it has only addresses (no delegated prefixes) assigned by a DHCP server to determine if it is still connected to the same link when the client detects a change in network information as described in Section 18.2.12.
如第18.2.12节所述，当客户端检测到网络信息发生变化时，客户端仅使用DHCP服务器分配的地址（无委派前缀）来确定其是否仍连接到同一链路。
The client sets the "msg-type" field to CONFIRM. The client generates a transaction ID and inserts this value in the "transaction-id" field.
客户端将“msg type”字段设置为确认。客户端生成一个事务ID并将该值插入“事务ID”字段。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client includes IA options for all of the IAs assigned to the interface for which the Confirm message is being sent. The IA options include all of the addresses the client currently has associated with those IAs. The client SHOULD set the T1 and T2 fields in any IA_NA options (see Section 21.4) and the preferred-lifetime and valid-lifetime fields in the IA Address options (see Section 21.6) to 0, as the server will ignore these fields.
客户端包括分配给发送确认消息的接口的所有IA的IA选项。IA选项包括客户端当前与这些IAs关联的所有地址。客户端应将任何IA_NA选项（见第21.4节）中的T1和T2字段以及IA地址选项（见第21.6节）中的首选生存期和有效生存期字段设置为0，因为服务器将忽略这些字段。
The first Confirm message from the client on the interface MUST be delayed by a random amount of time between 0 and CNF_MAX_DELAY. The client transmits the message according to Section 15, using the following parameters:
来自接口上客户端的第一条确认消息必须延迟0到CNF_MAX_DELAY之间的随机时间量。客户端使用以下参数根据第15节传输消息：
IRT CNF_TIMEOUT
IRT CNF_超时
MRT CNF_MAX_RT
捷运CNF_MAX_RT
MRC 0
MRC 0
MRD CNF_MAX_RD
MRD CNF_MAX_路
If the client receives no responses before the message transmission process terminates, as described in Section 15, the client SHOULD continue to use any leases, using the last known lifetimes for those leases, and SHOULD continue to use any other previously obtained configuration parameters.
如第15节所述，如果客户机在消息传输过程终止前未收到响应，则客户机应继续使用任何租约，使用这些租约的最后一个已知生存期，并应继续使用先前获得的任何其他配置参数。
To extend the preferred and valid lifetimes for the leases assigned to the IAs and obtain new addresses or delegated prefixes for IAs, the client sends a Renew message to the server from which the leases were obtained; the Renew message includes IA options for the IAs whose lease lifetimes are to be extended. The client includes IA Address options (see Section 21.6) within IA_NA (see Section 21.4) and IA_TA (see Section 21.5) options for the addresses assigned to the IAs. The client includes IA Prefix options (see Section 21.22) within IA_PD options (see Section 21.21) for the delegated prefixes assigned to the IAs.
为了延长分配给IAs的租约的首选和有效生存期，并获取IAs的新地址或委派前缀，客户端向获取租约的服务器发送续订消息；续订消息包括要延长租赁寿命的IAs的IA选项。客户在IA_NA（见第21.4节）和IA_TA（见第21.5节）中包括分配给IAs地址的IA地址选项（见第21.6节）。对于分配给IAs的授权前缀，客户机在IA_PD选项（见第21.21节）中包括IA前缀选项（见第21.22节）。
The server controls the time at which the client should contact the server to extend the lifetimes on assigned leases through the T1 and T2 values assigned to an IA. However, as the client SHOULD renew/rebind all IAs from the server at the same time, the client MUST select T1 and T2 times from all IA options that will guarantee that the client initiates transmissions of Renew/Rebind messages not later than at the T1/T2 times associated with any of the client's bindings (earliest T1/T2).
服务器通过分配给IA的T1和T2值控制客户端应与服务器联系以延长分配租约的生存期的时间。但是，由于客户端应同时从服务器续订/重新绑定所有IA，因此客户端必须从所有IA选项中选择T1和T2时间，以确保客户端在与任何客户端绑定相关联的T1/T2时间（最早的T1/T2）内启动续订/重新绑定消息的传输。
At time T1, the client initiates a Renew/Reply message exchange to extend the lifetimes on any leases in the IA.
在时间T1，客户端发起续订/应答消息交换，以延长IA中任何租约的生存期。
A client MUST also initiate a Renew/Reply message exchange before time T1 if the client's link-local address used in previous interactions with the server is no longer valid and it is willing to receive Reconfigure messages.
如果客户机在以前与服务器的交互中使用的链路本地地址不再有效并且愿意接收重新配置消息，则客户机还必须在时间T1之前启动续订/回复消息交换。
If T1 or T2 had been set to 0 by the server (for an IA_NA or IA_PD) or there are no T1 or T2 times (for an IA_TA) in a previous Reply, the client may, at its discretion, send a Renew or Rebind message, respectively. The client MUST follow the rules defined in Section 14.2.
如果服务器（对于IA_NA或IA_PD）将T1或T2设置为0，或者在以前的回复中没有T1或T2时间（对于IA_TA），则客户端可以自行决定分别发送续订或重新绑定消息。客户必须遵守第14.2节规定的规则。
The client sets the "msg-type" field to RENEW. The client generates a transaction ID and inserts this value in the "transaction-id" field.
客户端将“消息类型”字段设置为续订。客户端生成一个事务ID并将该值插入“事务ID”字段。
The client MUST include a Server Identifier option (see Section 21.3) in the Renew message, identifying the server with which the client most recently communicated.
客户机必须在续订消息中包含服务器标识符选项（见第21.3节），用于标识客户机最近与之通信的服务器。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server. The client adds any appropriate options, including one or more IA options.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。客户端添加任何适当的选项，包括一个或多个IA选项。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
For IAs to which leases have been assigned, the client includes a corresponding IA option containing an IA Address option for each address assigned to the IA and an IA Prefix option for each prefix assigned to the IA. The client MUST NOT include addresses and prefixes in any IA option that the client did not obtain from the server or that are no longer valid (that have a valid lifetime of 0).
对于已分配租约的IAs，客户机包括相应的IA选项，其中包含分配给IA的每个地址的IA地址选项和分配给IA的每个前缀的IA前缀选项。客户端不能在任何IA选项中包含地址和前缀，这些地址和前缀不是客户端从服务器获得的，或者不再有效（有效生存期为0）。
The client MAY include an IA option for each binding it desires but has been unable to obtain. In this case, if the client includes the IA_PD option to request prefix delegation, the client MAY include the IA Prefix option encapsulated within the IA_PD option, with the "IPv6-prefix" field set to 0 and the "prefix-length" field set to the desired length of the prefix to be delegated. The server MAY use this value as a hint for the prefix length. The client SHOULD NOT include an IA Prefix option with the "IPv6-prefix" field set to 0 unless it is supplying a hint for the prefix length.
客户可能会为其希望但无法获得的每个绑定提供IA选项。在这种情况下，如果客户端包括IA_PD选项以请求前缀委派，则客户端可以包括封装在IA_PD选项内的IA前缀选项，其中“IPv6前缀”字段设置为0，“前缀长度”字段设置为要委派的前缀的所需长度。服务器可以使用此值作为前缀长度的提示。客户端不应包含“IPv6前缀”字段设置为0的IA前缀选项，除非它提供前缀长度提示。
The client includes an Option Request option (see Section 21.7) to request the SOL_MAX_RT option (see Section 21.24) and any other options the client is interested in receiving. The client MAY include options with data values as hints to the server about parameter values the client would like to have returned.
客户包括一个选项请求选项（见第21.7节）以请求SOL_MAX_RT选项（见第21.24节）以及客户有兴趣接收的任何其他选项。客户机可能包括带有数据值的选项，作为向服务器提示客户机希望返回的参数值。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT REN_TIMEOUT
IRT RENU超时
MRT REN_MAX_RT
捷运站
MRC 0
MRC 0
MRD Remaining time until earliest T2
MRD到最早T2的剩余时间
The message exchange is terminated when the earliest time T2 is reached. While the client is responding to a Reconfigure, the client ignores and discards any additional Reconfigure messages it may receive.
消息交换在到达最早时间T2时终止。当客户端响应重新配置时，客户端会忽略并丢弃它可能收到的任何其他重新配置消息。
The message exchange is terminated when the earliest time T2 is reached, at which point the client begins the Rebind message exchange (see Section 18.2.5).
当到达最早时间T2时，消息交换终止，此时客户端开始重新绑定消息交换（见第18.2.5节）。
At time T2 (which will only be reached if the server to which the Renew message was sent starting at time T1 has not responded), the client initiates a Rebind/Reply message exchange with any available server.
在时间T2（仅当从时间T1开始向其发送续订消息的服务器没有响应时，才会到达该时间T2），客户端启动与任何可用服务器的重新绑定/回复消息交换。
A Rebind is also used to verify delegated prefix bindings but with different retransmission parameters as described in Section 18.2.3.
重新绑定也用于验证委托前缀绑定，但具有第18.2.3节所述的不同重传参数。
The client constructs the Rebind message as described in Section 18.2.4, with the following differences:
客户端按照第18.2.4节所述构造重新绑定消息，但有以下区别：
- The client sets the "msg-type" field to REBIND.
- 客户端将“msg type”字段设置为重新绑定。
- The client does not include the Server Identifier option (see Section 21.3) in the Rebind message.
- 客户端在重新绑定消息中不包括服务器标识符选项（请参阅第21.3节）。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT REB_TIMEOUT
IRT REB_超时
MRT REB_MAX_RT
捷运快线快线
MRC 0
MRC 0
MRD Remaining time until valid lifetimes of all leases in all IAs have expired
MRD剩余时间，直至所有IAs中所有租赁的有效寿命到期
If all leases for an IA have expired, the client may choose to include this IA in subsequent Rebind messages to indicate that the client is interested in assignment of the leases to this IA.
如果IA的所有租约都已到期，则客户端可以选择在随后的重新绑定消息中包括该IA，以表明客户端有兴趣将租约分配给该IA。
The message exchange is terminated when the valid lifetimes of all leases across all IAs have expired, at which time the client uses the Solicit message to locate a new DHCP server and sends a Request for the expired IAs to the new server. If the terminated Rebind exchange was initiated as a result of receiving a Reconfigure message, the client ignores and discards the Reconfigure message.
当跨所有IAs的所有租约的有效生存期过期时，消息交换终止，此时客户端使用请求消息定位新的DHCP服务器，并向新服务器发送过期IAs的请求。如果终止的重新绑定交换是由于接收到重新配置消息而启动的，则客户端将忽略并丢弃该重新配置消息。
The client uses an Information-request message to obtain configuration information without having addresses and/or delegated prefixes assigned to it.
客户端使用信息请求消息来获取配置信息，而无需为其分配地址和/或委派前缀。
The client sets the "msg-type" field to INFORMATION-REQUEST. The client generates a transaction ID and inserts this value in the "transaction-id" field.
客户端将“msg type”字段设置为INFORMATION-REQUEST。客户端生成一个事务ID并将该值插入“事务ID”字段。
The client SHOULD include a Client Identifier option (see Section 21.2) to identify itself to the server (however, see Section 4.3.1 of [RFC7844] for reasons why a client may not want to include this option). If the client does not include a Client Identifier option, the server will not be able to return any client-specific options to the client, or the server may choose not to respond to the message at all.
客户机应包括一个客户机标识符选项（见第21.2节），以向服务器标识自己（但是，客户机可能不希望包括此选项的原因，请参见[RFC7844]第4.3.1节）。如果客户端不包括客户端标识符选项，服务器将无法向客户端返回任何特定于客户端的选项，或者服务器可能选择根本不响应消息。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client MUST include an Option Request option (see Section 21.7) to request the INF_MAX_RT option (see Section 21.25), the Information Refresh Time option (see Section 21.23), and any other options the client is interested in receiving. The client MAY include options with data values as hints to the server about parameter values the client would like to have returned.
客户机必须包括一个选项请求选项（见第21.7节）以请求INF_MAX_RT选项（见第21.25节）、信息刷新时间选项（见第21.23节）以及客户机希望接收的任何其他选项。客户机可能包括带有数据值的选项，作为向服务器提示客户机希望返回的参数值。
When responding to a Reconfigure, the client includes a Server Identifier option (see Section 21.3) with the identifier from the Reconfigure message to which the client is responding.
当响应重新配置时，客户机包括一个服务器标识符选项（参见第21.3节），其中的标识符来自客户机响应的重新配置消息。
The first Information-request message from the client on the interface MUST be delayed by a random amount of time between 0 and INF_MAX_DELAY. The client transmits the message according to Section 15, using the following parameters:
来自接口上客户端的第一条信息请求消息必须延迟0到INF_MAX_DELAY之间的随机时间量。客户端使用以下参数根据第15节传输消息：
IRT INF_TIMEOUT
IRT INF\u超时
MRT INF_MAX_RT
MRT INF\u MAX\u RT
MRC 0
MRC 0
MRD 0
MRD 0
To release one or more leases, a client sends a Release message to the server.
要释放一个或多个租约，客户端将向服务器发送释放消息。
The client sets the "msg-type" field to RELEASE. The client generates a transaction ID and places this value in the "transaction-id" field.
客户端将“msg type”字段设置为RELEASE。客户端生成一个事务ID，并将该值放在“事务ID”字段中。
The client places the identifier of the server that allocated the lease(s) in a Server Identifier option (see Section 21.3).
客户机将分配租约的服务器的标识符放在服务器标识符选项中（参见第21.3节）。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client includes options containing the IAs for the leases it is releasing in the "options" field. The leases to be released MUST be included in the IAs. Any leases for the IAs the client wishes to continue to use MUST NOT be added to the IAs.
客户在“选项”字段中包含包含其正在发布的租赁的IAs的选项。待解除的租赁必须包括在IAs中。客户希望继续使用的任何IAs租赁不得添加到IAs中。
The client MUST stop using all of the leases being released before the client begins the Release message exchange process. For an address, this means the address MUST have been removed from the interface. For a delegated prefix, this means the prefix MUST have been advertised with a Preferred Lifetime and a Valid Lifetime of 0 in a Router Advertisement message as described in part (e) of Section 5.5.3 of [RFC4862]; also see requirement L-13 in Section 4.3 of [RFC7084].
在客户端开始释放消息交换过程之前，客户端必须停止使用正在释放的所有租约。对于地址，这意味着该地址必须已从接口中删除。对于委托前缀，这意味着该前缀必须在[RFC4862]第5.5.3节第（e）部分所述的路由器公告消息中以首选生存期和有效生存期0进行公告；另见[RFC7084]第4.3节中的要求L-13。
The client MUST NOT use any of the addresses it is releasing as the source address in the Release message or in any subsequently transmitted message.
客户端不得将其正在发布的任何地址用作发布消息或任何后续传输消息中的源地址。
Because Release messages may be lost, the client should retransmit the Release if no Reply is received. However, there are scenarios where the client may not wish to wait for the normal retransmission timeout before giving up (e.g., on power down). Implementations SHOULD retransmit one or more times but MAY choose to terminate the retransmission procedure early.
因为发布消息可能会丢失，所以如果没有收到回复，客户端应该重新传输发布。但是，在某些情况下，客户端可能不希望在放弃之前等待正常的重新传输超时（例如，断电）。实现应该重新传输一次或多次，但可以选择提前终止重新传输过程。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT REL_TIMEOUT
IRT REL_超时
MRT 0
地铁0
MRC REL_MAX_RC
MRC REL_MAX_RC
MRD 0
MRD 0
If leases are released but the Reply from a DHCP server is lost, the client will retransmit the Release message, and the server may respond with a Reply indicating a status of NoBinding. Therefore, the client does not treat a Reply message with a status of NoBinding in a Release message exchange as if it indicates an error.
如果租约被释放，但来自DHCP服务器的回复丢失，则客户端将重新传输释放消息，服务器可能会用指示NoBinding状态的回复进行响应。因此，客户端不会将发布消息交换中状态为NoBinding的回复消息视为指示错误。
Note that if the client fails to release the lease, each lease assigned to the IA will be reclaimed by the server when the valid lifetime of that lease expires.
请注意，如果客户端未能释放租约，则分配给IA的每个租约将在该租约的有效生存期到期时由服务器收回。
If a client detects that one or more addresses assigned to it by a server are already in use by another node, the client sends a Decline message to the server to inform it that the address is suspect.
如果客户端检测到由服务器分配给它的一个或多个地址已被另一个节点使用，则客户端将向服务器发送拒绝消息，告知该地址可疑。
The Decline message is not used in prefix delegation; thus, the client MUST NOT include IA_PD options (see Section 21.21) in the Decline message.
拒绝消息不用于前缀委派；因此，客户不得在拒绝消息中包含IA_PD选项（见第21.21节）。
The client sets the "msg-type" field to DECLINE. The client generates a transaction ID and places this value in the "transaction-id" field.
客户端将“消息类型”字段设置为拒绝。客户端生成一个事务ID，并将该值放在“事务ID”字段中。
The client places the identifier of the server that allocated the address(es) in a Server Identifier option (see Section 21.3).
客户端将分配地址的服务器的标识符放在服务器标识符选项中（参见第21.3节）。
The client MUST include a Client Identifier option (see Section 21.2) to identify itself to the server.
客户机必须包括一个客户机标识符选项（见第21.2节），以便向服务器标识自己。
The client MUST include an Elapsed Time option (see Section 21.9) to indicate how long the client has been trying to complete the current DHCP message exchange.
客户端必须包含一个已用时间选项（见第21.9节），以指示客户端尝试完成当前DHCP消息交换的时间。
The client includes options containing the IAs for the addresses it is declining in the "options" field. The addresses to be declined MUST be included in the IAs. Any addresses for the IAs the client wishes to continue to use should not be added to the IAs.
客户机在“选项”字段中包含包含其拒绝的地址的IAs的选项。要拒绝的地址必须包含在IAs中。客户希望继续使用的IAs地址不应添加到IAs中。
The client MUST NOT use any of the addresses it is declining as the source address in the Decline message or in any subsequently transmitted message.
客户端不得将其拒绝的任何地址用作拒绝消息或任何后续传输消息中的源地址。
The client transmits the message according to Section 15, using the following parameters:
客户端使用以下参数根据第15节传输消息：
IRT DEC_TIMEOUT
IRT DEC_超时
MRT 0
地铁0
MRC DEC_MAX_RC
MRC DEC_MAX_RC
MRD 0
MRD 0
If addresses are declined but the Reply from a DHCP server is lost, the client will retransmit the Decline message, and the server may respond with a Reply indicating a status of NoBinding. Therefore, the client does not treat a Reply message with a status of NoBinding in a Decline message exchange as if it indicates an error.
如果地址被拒绝，但来自DHCP服务器的回复丢失，客户端将重新传输拒绝消息，服务器可能会用指示NoBinding状态的回复进行响应。因此，在拒绝消息交换中，客户端不会将状态为NoBinding的回复消息视为指示错误。
The client SHOULD NOT send a Release message for other bindings it may have received just because it sent a Decline message. The client SHOULD retain the non-conflicting bindings. The client SHOULD treat the failure to acquire a binding (due to the conflict) as equivalent to not having received the binding, insofar as how it behaves when sending Renew and Rebind messages.
客户端不应该仅仅因为发送了拒绝消息就发送它可能已收到的其他绑定的发布消息。客户端应保留非冲突绑定。客户端应将未能获取绑定（由于冲突）视为未收到绑定，只要它在发送续订和重新绑定消息时的行为。
Upon receipt of one or more valid Advertise messages, the client selects one or more Advertise messages based upon the following criteria.
在收到一个或多个有效的播发消息后，客户端根据以下条件选择一个或多个播发消息。
- Those Advertise messages with the highest server preference value SHOULD be preferred over all other Advertise messages. The client MAY choose a less preferred server if that server has a better set of advertised parameters, such as the available set of IAs, as well as the set of other configuration options advertised.
- 那些具有最高服务器首选项值的播发消息应优先于所有其他播发消息。如果服务器具有更好的公布参数集（例如可用的IAs集）以及公布的其他配置选项集，则客户端可以选择较不首选的服务器。
- Within a group of Advertise messages with the same server preference value, a client MAY select those servers whose Advertise messages advertise information of interest to the client.
- 在具有相同服务器首选项值的一组播发消息中，客户机可以选择那些其播发消息播发客户机感兴趣的信息的服务器。
Once a client has selected Advertise message(s), the client will typically store information about each server, such as the server preference value, addresses advertised, when the advertisement was received, and so on.
一旦客户机选择了播发消息，客户机通常将存储关于每个服务器的信息，例如服务器首选项值、播发地址、接收播发的时间等。
In practice, this means that the client will maintain independent per-IA state machines for each selected server.
实际上，这意味着客户端将为每个选定的服务器维护独立的每IA状态机。
If the client needs to select an alternate server in the case that a chosen server does not respond, the client chooses the next server according to the criteria given above.
如果客户机需要在所选服务器未响应的情况下选择备用服务器，则客户机将根据上述标准选择下一台服务器。
The client MUST process any SOL_MAX_RT option (see Section 21.24) and INF_MAX_RT option (see Section 21.25) present in an Advertise message, even if the message contains a Status Code option (see Section 21.13) indicating a failure, and the Advertise message will be discarded by the client. A client SHOULD only update its SOL_MAX_RT and INF_MAX_RT values if all received Advertise messages that contained the corresponding option specified the same value; otherwise, it should use the default value (see Section 7.6).
客户端必须处理播发消息中存在的任何SOL_MAX_RT选项（见第21.24节）和INF_MAX_RT选项（见第21.25节），即使消息包含指示失败的状态代码选项（见第21.13节），客户端也会丢弃播发消息。如果所有接收到的包含相应选项的播发消息都指定了相同的值，则客户端只应更新其SOL_MAX_RT和INF_MAX_RT值；否则，应使用默认值（见第7.6节）。
The client MUST ignore any Advertise message that contains no addresses (IA Address options (see Section 21.6) encapsulated in IA_NA options (see Section 21.4) or IA_TA options (see Section 21.5)) and no delegated prefixes (IA Prefix options (see Section 21.22) encapsulated in IA_PD options (see Section 21.21)), with the exception that the client:
客户必须忽略任何不包含IA_-NA选项（见第21.4节）或IA_-TA选项（见第21.5节））中封装的地址（IA地址选项（见第21.6节）和IA_-PD选项（见第21.21节）中封装的委托前缀（IA前缀选项（见第21.22节））的播发消息，但客户：
- MUST process an included SOL_MAX_RT option and
- 必须处理包含的SOL_MAX_RT选项，并且
- MUST process an included INF_MAX_RT option.
- 必须处理包含的INF\u MAX\u RT选项。
A client can record in an activity log or display to the user any associated status message(s).
客户端可以在活动日志中记录或向用户显示任何关联的状态消息。
The client ignoring an Advertise message MUST NOT restart the Solicit retransmission timer.
忽略播发消息的客户端不得重新启动请求重传计时器。
Upon the receipt of a valid Reply message in response to a Solicit with a Rapid Commit option (see Section 21.14), Request, Confirm, Renew, Rebind, or Information-request message, the client extracts the top-level Status Code option (see Section 21.13) if present.
在收到有效的回复消息以响应带有快速提交选项（见第21.14节）、请求、确认、续订、重新绑定或信息请求消息的请求后，客户机将提取顶级状态代码选项（见第21.13节）。
The client MUST process any SOL_MAX_RT option (see Section 21.24) and INF_MAX_RT option (see Section 21.25) present in a Reply message, even if the message contains a Status Code option indicating a failure.
客户端必须处理回复消息中出现的任何SOL_MAX_RT选项（见第21.24节）和INF_MAX_RT选项（见第21.25节），即使消息包含指示故障的状态代码选项。
If the client receives a Reply message with a status code of UnspecFail, the server is indicating that it was unable to process the client's message due to an unspecified failure condition. If the client retransmits the original message to the same server to retry the desired operation, the client MUST limit the rate at which it retransmits the message and limit the duration of the time during which it retransmits the message (see Section 14.1).
如果客户端收到状态代码为UnspecFail的回复消息，则服务器表示由于未指定的故障条件，它无法处理客户端的消息。如果客户端将原始消息重新传输到同一服务器以重试所需操作，则客户端必须限制其重新传输消息的速率，并限制其重新传输消息的持续时间（参见第14.1节）。
If the client receives a Reply message with a status code of UseMulticast, the client records the receipt of the message and sends subsequent messages to the server through the interface on which the message was received using multicast. The client resends the original message using multicast.
如果客户端接收到状态代码为UseMulticast的回复消息，则客户端会记录消息的接收情况，并通过使用多播接收消息的接口将后续消息发送到服务器。客户端使用多播重新发送原始消息。
Otherwise (no status code or another status code), the client processes the Reply as described below based on the original message for which the Reply was received.
否则（无状态代码或其他状态代码），客户机将根据收到回复的原始消息按如下所述处理回复。
The client MAY choose to report any status code or message from the Status Code option in the Reply message.
客户端可以从回复消息中的状态代码选项中选择报告任何状态代码或消息。
When a client received a configuration option in an earlier Reply and then sends a Renew, Rebind, or Information-request and the requested option is not present in the Reply, the client SHOULD stop using the previously received configuration information. In other words, the client should behave as if it never received this configuration option and return to the relevant default state. If there is no viable way to stop using the received configuration information, the values received/configured from the option MAY persist if there are no other sources for that data and they have no external impact. For
当客户机在先前的答复中收到配置选项，然后发送续订、重新绑定或信息请求，而请求的选项在答复中不存在时，客户机应停止使用先前收到的配置信息。换句话说，客户机的行为应该像从未收到此配置选项一样，并返回到相关的默认状态。如果没有可行的方法停止使用接收到的配置信息，则如果没有其他数据源，并且没有外部影响，则从选项接收/配置的值可能会持续存在。对于
example, a client that previously received a Client FQDN option (see [RFC4704]) and used it to set up its hostname is allowed to continue using it if there is no reasonable way for a node to unset its hostname and it has no external impact. As a counter-example, a client that previously received an NTP server address from the DHCP server and does not receive it anymore MUST stop using the configured NTP server address. The client SHOULD be open to other sources of the same configuration information. This behavior does not apply to any IA options, as their processing is described in detail in the next section.
例如，如果节点无法合理地取消设置其主机名，并且没有外部影响，则允许以前接收到客户机FQDN选项（请参见[RFC4704]）并使用该选项设置其主机名的客户机继续使用该选项。作为反例，以前从DHCP服务器接收到NTP服务器地址但不再接收该地址的客户端必须停止使用配置的NTP服务器地址。客户端应该对相同配置信息的其他来源开放。此行为不适用于任何IA选项，因为它们的处理将在下一节中详细描述。
When a client receives a requested option that has an updated value from what was previously received, the client SHOULD make use of that updated value as soon as possible for its configuration information.
当客户机收到一个请求的选项，该选项具有以前收到的更新值时，客户机应尽快将该更新值用于其配置信息。
18.2.10.1. Reply for Solicit (with Rapid Commit), Request, Renew, or Rebind
18.2.10.1. 回复请求（快速提交）、请求、续订或重新绑定
If the client receives a NotOnLink status from the server in response to a Solicit (with a Rapid Commit option; see Section 21.14) or a Request, the client can either reissue the message without specifying any addresses or restart the DHCP server discovery process (see Section 18).
如果客户端从服务器接收到NotOnLink状态以响应请求（具有快速提交选项；请参阅第21.14节）或请求，则客户端可以在不指定任何地址的情况下重新发出消息，也可以重新启动DHCP服务器发现过程（请参阅第18节）。
If the Reply was received in response to a Solicit (with a Rapid Commit option), Request, Renew, or Rebind message, the client updates the information it has recorded about IAs from the IA options contained in the Reply message:
如果收到回复是对请求（具有快速提交选项）、请求、续订或重新绑定消息的响应，则客户机将根据回复消息中包含的IA选项更新其记录的有关IAs的信息：
- Calculate T1 and T2 times (based on T1 and T2 values sent in the packet and the packet reception time), if appropriate for the IA type.
- 如果适用于IA类型，计算T1和T2时间（基于数据包中发送的T1和T2值以及数据包接收时间）。
- Add any new leases in the IA option to the IA as recorded by the client.
- 将IA选项中的任何新租约添加到客户记录的IA中。
- Update lifetimes for any leases in the IA option that the client already has recorded in the IA.
- 更新客户机已在IA中记录的IA选项中任何租约的生存期。
- Discard any leases from the IA, as recorded by the client, that have a valid lifetime of 0 in the IA Address or IA Prefix option.
- 放弃来自IA的、由客户端记录的、在IA地址或IA前缀选项中有效生存期为0的任何租约。
- Leave unchanged any information about leases the client has recorded in the IA but that were not included in the IA from the server.
- 保留有关客户端已记录在IA中但未包含在服务器IA中的租约的任何信息不变。
If the client can operate with the addresses and/or prefixes obtained from the server:
如果客户端可以使用从服务器获得的地址和/或前缀进行操作：
- The client uses the addresses, delegated prefixes, and other information from any IAs that do not contain a Status Code option with the NoAddrsAvail or NoPrefixAvail status code. The client MAY include the IAs for which it received the NoAddrsAvail or NoPrefixAvail status code, with no addresses or prefixes, in subsequent Renew and Rebind messages sent to the server, to retry obtaining the addresses or prefixes for these IAs.
- 客户机使用地址、委派前缀和来自任何不包含状态代码选项的IAs的其他信息，这些信息包含NoAddrsAvail或NoPrefixAvail状态代码。客户端可以在发送到服务器的后续续订和重新绑定消息中包括接收到无地址或前缀的NOADDRISAVAIL或NoPrefixAvail状态代码的IAs，以重试获取这些IAs的地址或前缀。
- The client MUST perform duplicate address detection as per Section 5.4 of [RFC4862], which does list some exceptions, on each of the received addresses in any IAs on which it has not performed duplicate address detection during processing of any of the previous Reply messages from the server. The client performs the duplicate address detection before using the received addresses for any traffic. If any of the addresses are found to be in use on the link, the client sends a Decline message to the server for those addresses as described in Section 18.2.8.
- 客户机必须按照[RFC4862]第5.4节的规定执行重复地址检测，该节确实列出了在处理来自服务器的任何先前回复消息期间未执行重复地址检测的任何IAs中接收到的每个地址的一些例外情况。客户端在将接收到的地址用于任何通信之前执行重复地址检测。如果发现任何地址在链路上使用，客户端将向服务器发送拒绝消息，以获取第18.2.8节所述的地址。
- For each assigned address that does not have any associated reachability information (see the definition of "on-link" in Section 2.1 of [RFC4861]), in order to avoid the problems described in [RFC4943], the client MUST NOT assume that any addresses are reachable on-link as a result of receiving an IA_NA or IA_TA. Addresses obtained from an IA_NA or IA_TA MUST NOT be used to form an implicit prefix with a length other than 128.
- 对于没有任何相关可达性信息的每个分配地址（参见[RFC4861]第2.1节中“链路上”的定义），为了避免[RFC4943]中描述的问题，客户机不得假设由于接收IA_-NA或IA_-TA而在链路上可访问任何地址。从IA_NA或IA_TA获取的地址不得用于形成长度不是128的隐式前缀。
- For each delegated prefix, the client assigns a subnet to each of the links to which the associated interfaces are attached.
- 对于每个委派的前缀，客户机将子网分配给关联接口连接到的每个链路。
When a client subnets a delegated prefix, it must assign additional bits to the prefix to generate unique, longer prefixes. For example, if the client in Figure 1 were delegated 2001:db8:0::/48, it might generate 2001:db8:0:1::/64 and 2001:db8:0:2::/64 for assignment to the two links in the subscriber network. If the client were delegated 2001:db8:0::/48 and 2001:db8:5::/48, it might assign 2001:db8:0:1::/64 and 2001:db8:5:1::/64 to one of the links, and 2001:db8:0:2::/64 and 2001:db8:5:2::/64 for assignment to the other link.
当客户端将委托前缀子网化时，它必须为前缀分配额外的位，以生成唯一的、更长的前缀。例如，如果图1中的客户机被委托为2001:db8:0:：/48，则它可能会生成2001:db8:0:1:：/64和2001:db8:0:2:：/64以分配给订户网络中的两个链路。如果委托给客户机的是2001:db8:0:：/48和2001:db8:5:：/48，则可能会将2001:db8:0:1:：/64和2001:db8:5:1:：/64分配给其中一个链接，将2001:db8:0:2:：/64和2001:db8:5:2:：/64分配给另一个链接。
If the client uses a delegated prefix to configure addresses on interfaces on itself or other nodes behind it, the preferred and valid lifetimes of those addresses MUST be no longer than the remaining preferred and valid lifetimes, respectively, for the delegated prefix at any time. In particular, if the delegated
如果客户端使用委派前缀在其自身或其后面的其他节点上的接口上配置地址，则这些地址的首选和有效生存期在任何时候都不得分别长于委派前缀的剩余首选和有效生存期。特别是，如果
prefix or a prefix derived from it is advertised for stateless address autoconfiguration [RFC4862], the advertised preferred and valid lifetimes MUST NOT exceed the corresponding remaining lifetimes of the delegated prefix.
为无状态地址自动配置[RFC4862]播发前缀或从其派生的前缀，播发的首选和有效生存期不得超过委派前缀的相应剩余生存期。
Management of the specific configuration information is detailed in the definition of each option in Section 21.
具体配置信息的管理详见第21节中每个选项的定义。
If the Reply message contains any IAs but the client finds no usable addresses and/or delegated prefixes in any of these IAs, the client may either try another server (perhaps restarting the DHCP server discovery process) or use the Information-request message to obtain other configuration information only.
如果回复消息包含任何IAs，但客户端在这些IAs中找不到可用地址和/或委派前缀，则客户端可以尝试另一台服务器（可能重新启动DHCP服务器发现过程），或者使用信息请求消息仅获取其他配置信息。
When the client receives a Reply message in response to a Renew or Rebind message, the client:
当客户端收到响应续订或重新绑定消息的回复消息时，客户端：
- Sends a Request message to the server that responded if any of the IAs in the Reply message contain the NoBinding status code. The client places IA options in this message for all IAs. The client continues to use other bindings for which the server did not return an error.
- 如果回复消息中的任何IAs包含NoBinding状态代码，则向响应的服务器发送请求消息。客户端在此消息中为所有IA放置IA选项。客户端继续使用服务器未返回错误的其他绑定。
- Sends a Renew/Rebind if any of the IAs are not in the Reply message, but as this likely indicates that the server that responded does not support that IA type, sending immediately is unlikely to produce a different result. Therefore, the client MUST rate-limit its transmissions (see Section 14.1) and MAY just wait for the normal retransmission time (as if the Reply message had not been received). The client continues to use other bindings for which the server did return information.
- 如果任何IA不在回复消息中，则发送续订/重新绑定，但这可能表明响应的服务器不支持该IA类型，因此立即发送不太可能产生不同的结果。因此，客户端必须对其传输进行速率限制（见第14.1节），并且可以只等待正常的重新传输时间（就好像没有收到回复消息一样）。客户端继续使用服务器返回信息的其他绑定。
- Otherwise accepts the information in the IA.
- 否则接受IA中的信息。
Whenever a client restarts the DHCP server discovery process or selects an alternate server as described in Section 18.2.9, the client SHOULD stop using all the addresses and delegated prefixes for which it has bindings and try to obtain all required leases from the new server. This facilitates the client using a single state machine for all bindings.
每当客户机重新启动DHCP服务器发现过程或如第18.2.9节所述选择备用服务器时，客户机应停止使用其具有绑定的所有地址和委派前缀，并尝试从新服务器获取所有必需的租约。这有助于客户机对所有绑定使用单个状态机。
When the client receives a valid Reply message in response to a Release message, the client considers the Release event completed, regardless of the Status Code option (see Section 21.13) returned by the server.
当客户端收到响应发布消息的有效回复消息时，客户端认为发布事件已完成，而不管服务器返回的状态代码选项（见第21.13节）。
When the client receives a valid Reply message in response to a Decline message, the client considers the Decline event completed, regardless of the Status Code option(s) returned by the server.
当客户端收到响应拒绝消息的有效回复消息时，无论服务器返回的状态代码选项如何，客户端都会认为拒绝事件已完成。
If the client receives any Reply messages that indicate a status of Success (explicit or implicit), the client can use the addresses in the IA and ignore any messages that indicate a NotOnLink status. When the client only receives one or more Reply messages with the NotOnLink status in response to a Confirm message, the client performs DHCP server discovery as described in Section 18.
如果客户端接收到任何指示成功状态（显式或隐式）的回复消息，则客户端可以使用IA中的地址并忽略任何指示NotOnLink状态的消息。当客户端仅接收到一个或多个响应确认消息的NotOnLink状态的回复消息时，客户端将按照第18节所述执行DHCP服务器发现。
Refer to Section 21.23 for details on how the Information Refresh Time option (whether or not present in the Reply) should be handled by the client.
有关客户端应如何处理信息刷新时间选项（无论回复中是否存在）的详细信息，请参阅第21.23节。
A client receives Reconfigure messages sent to UDP port 546 on interfaces for which it has acquired configuration information through DHCP. These messages may be sent at any time. Since the results of a reconfiguration event may affect application-layer programs, the client SHOULD log these events and MAY notify these programs of the change through an implementation-specific interface.
客户端在其通过DHCP获取配置信息的接口上接收发送到UDP端口546的重新配置消息。这些信息可以随时发送。由于重新配置事件的结果可能会影响应用层程序，因此客户端应记录这些事件，并可通过特定于实现的接口将更改通知这些程序。
Upon receipt of a valid Reconfigure message, the client responds with a Renew message, a Rebind message, or an Information-request message as indicated by the Reconfigure Message option (see Section 21.19). The client ignores the "transaction-id" field in the received Reconfigure message. While the transaction is in progress, the client discards any Reconfigure messages it receives.
在收到有效的重新配置消息后，客户机会以更新消息、重新绑定消息或信息请求消息响应，如重新配置消息选项所示（见第21.19节）。客户端忽略收到的重新配置消息中的“事务id”字段。当事务正在进行时，客户端将丢弃它接收到的任何重新配置消息。
The Reconfigure message acts as a trigger that signals the client to complete a successful message exchange. Once the client has received a Reconfigure, the client proceeds with the message exchange (retransmitting the Renew, Rebind, or Information-request message if necessary); the client MUST ignore any additional Reconfigure messages until the exchange is complete.
重新配置消息充当一个触发器，向客户机发送信号以完成成功的消息交换。一旦客户端收到重新配置，客户端将继续进行消息交换（如有必要，重新传输续订、重新绑定或信息请求消息）；在交换完成之前，客户端必须忽略任何其他重新配置消息。
Duplicate messages will be ignored because the client will begin the exchange after the receipt of the first Reconfigure. Retransmitted messages will either (1) trigger the exchange (if the first Reconfigure was not received by the client) or (2) be ignored. The server MAY discontinue retransmission of Reconfigure messages to the client once the server receives the Renew, Rebind, or Information-request message from the client.
重复的消息将被忽略，因为客户端将在收到第一次重新配置后开始交换。重新传输的消息将（1）触发交换（如果客户端未收到第一次重新配置），或（2）被忽略。一旦服务器从客户端接收到续订、重新绑定或信息请求消息，服务器就可以停止向客户端重新传输重新配置消息。
It might be possible for a duplicate or retransmitted Reconfigure to be sufficiently delayed (and delivered out of order) that it arrives at the client after the exchange (initiated by the original Reconfigure) has been completed. In this case, the client would initiate a redundant exchange. The likelihood of delayed and out-of-order delivery is small enough to be ignored. The consequence of the redundant exchange is inefficiency rather than incorrect operation.
重复或重新传输的重新配置可能会被充分延迟（并无序交付），以便在交换（由原始重新配置启动）完成后到达客户端。在这种情况下，客户端将启动冗余交换。延迟和无序交付的可能性很小，可以忽略不计。冗余交换的结果是效率低下，而不是操作不正确。
Whenever a client may have moved to a new link, the prefixes/addresses assigned to the interfaces on that link may no longer be appropriate for the link to which the client is attached. Examples of times when a client may have moved to a new link include the following:
每当客户端移动到新链接时，分配给该链接上接口的前缀/地址可能不再适用于客户端所连接的链接。客户机可能已移动到新链接的时间示例包括：
- The client reboots (and has stable storage and persistent DHCP state).
- 客户端将重新启动（并具有稳定的存储和持久的DHCP状态）。
- The client is reconnected to a link on which it has obtained leases.
- 客户端将重新连接到其已获得租约的链接。
- The client returns from sleep mode.
- 客户端从睡眠模式返回。
- The client changes access points (e.g., if using Wi-Fi technology).
- 客户端更改接入点（例如，如果使用Wi-Fi技术）。
When the client detects that it may have moved to a new link and it has obtained addresses and no delegated prefixes from a server, the client SHOULD initiate a Confirm/Reply message exchange. The client includes any IAs assigned to the interface that may have moved to a new link, along with the addresses associated with those IAs, in its Confirm message. Any responding servers will indicate whether those addresses are appropriate for the link to which the client is attached with the status in the Reply message it returns to the client.
当客户端检测到它可能已移动到新链接，并且已从服务器获取地址且没有委派前缀时，客户端应启动确认/回复消息交换。客户机在其确认消息中包括分配给接口的可能已移动到新链接的任何IAs，以及与这些IAs关联的地址。任何响应服务器都将指示这些地址是否适用于客户端所连接的链接，并在其返回给客户端的回复消息中显示状态。
If the client has any valid delegated prefixes obtained from the DHCP server, the client MUST initiate a Rebind/Reply message exchange as described in Section 18.2.5, with the exception that the retransmission parameters should be set as for the Confirm message (see Section 18.2.3). The client includes IA_NAs, IA_TAs, and IA_PDs, along with the associated leases, in its Rebind message.
如果客户机具有从DHCP服务器获得的任何有效委派前缀，则客户机必须按照第18.2.5节所述启动重新绑定/回复消息交换，但应为确认消息设置重新传输参数的情况除外（参见第18.2.3节）。客户端在其重新绑定消息中包括IA_NAs、IA_TA和IA_PDs以及相关的租约。
If the client has only obtained network information using Information-request/Reply message exchanges, the client MUST initiate an Information-request/Reply message exchange as described in Section 18.2.6.
如果客户仅通过信息请求/回复消息交换获得网络信息，则客户必须按照第18.2.6节所述启动信息请求/回复消息交换。
If not associated with one of the above-mentioned conditions, a client SHOULD initiate a Renew/Reply exchange (as if the T1 time expired) as described in Section 18.2.4 or an Information-request/ Reply exchange as described in Section 18.2.6 if the client detects a significant change regarding the prefixes available on the link (when new prefixes are added or existing prefixes are deprecated), as this may indicate a configuration change. However, a client MUST rate-limit such attempts to avoid flooding a server with requests when there are link issues (for example, only doing one of these at most every 30 seconds).
如果与上述条件之一无关，则如果客户端检测到链路上可用前缀的重大变化，则客户端应启动第18.2.4节所述的续订/回复交换（如同T1时间已过期），或第18.2.6节所述的信息请求/回复交换（当添加新前缀或不推荐使用现有前缀时），因为这可能表明配置发生了更改。但是，客户端必须对此类尝试进行评级限制，以避免在出现链接问题时（例如，最多每30秒只执行一次）向服务器发送请求。
For this discussion, the server is assumed to have been configured in an implementation-specific manner with configurations of interest to clients.
在本讨论中，假定服务器是以特定于实现的方式配置的，并且配置了客户机感兴趣的配置。
A server sends an Advertise message in response to each valid Solicit message it receives to announce the availability of the server to the client.
服务器发送一条播发消息以响应它接收到的每个有效请求消息，从而向客户端宣布服务器的可用性。
In most cases, the server will send a Reply in response to Request, Confirm, Renew, Rebind, Decline, Release, and Information-request messages sent by a client. The server will also send a Reply in response to a Solicit with a Rapid Commit option (see Section 21.14) when the server is configured to respond with committed lease assignments.
在大多数情况下，服务器将发送回复以响应客户端发送的请求、确认、续订、重新绑定、拒绝、释放和信息请求消息。当服务器配置为使用提交的租约分配进行响应时，服务器还将使用快速提交选项（参见第21.14节）发送响应请求的回复。
These Advertise and Reply messages MUST always contain the Server Identifier option (see Section 21.3) containing the server's DUID and the Client Identifier option (see Section 21.2) from the client message if one was present.
这些播发和回复消息必须始终包含服务器标识符选项（见第21.3节），其中包含服务器的DUID，如果存在，则包含客户端消息中的客户端标识符选项（见第21.2节）。
In most response messages, the server includes options containing configuration information for the client. The server must be aware of the recommendations on packet sizes and the use of fragmentation
在大多数响应消息中，服务器包含包含客户端配置信息的选项。服务器必须了解关于数据包大小和碎片使用的建议
as discussed in Section 5 of [RFC8200]. If the client included an Option Request option (see Section 21.7) in its message, the server includes options in the response message containing configuration parameters for all of the options identified in the Option Request option that the server has been configured to return to the client. The server MAY return additional options to the client if it has been configured to do so.
如[RFC8200]第5节所述。如果客户机在其消息中包含一个选项请求选项（见第21.7节），则服务器会在响应消息中包含选项，其中包含选项请求选项中标识的所有选项的配置参数，该选项已配置为服务器返回客户机。如果已将服务器配置为向客户端返回其他选项，则服务器可能会向客户端返回这些选项。
Any message sent from a client may arrive at the server encapsulated in one or more Relay-forward messages. The server MUST use the received message to construct the proper Relay-reply message to allow the response to the received message to be relayed through the same relay agents (in reverse order) as the original client message; see Section 19.3 for more details. The server may also need to record this information with each client in case it is needed to send a Reconfigure message at a later time, unless the server has been configured with addresses that can be used to send Reconfigure messages directly to the client (see Section 18.3.11). Note that servers that support leasequery [RFC5007] also need to record this information.
从客户端发送的任何消息都可能到达封装在一个或多个中继转发消息中的服务器。服务器必须使用接收到的消息构造适当的中继回复消息，以允许通过与原始客户端消息相同的中继代理（按相反顺序）中继对接收到的消息的响应；详见第19.3节。如果以后需要发送重新配置消息，服务器可能还需要在每个客户机上记录此信息，除非服务器配置了可用于直接向客户机发送重新配置消息的地址（见第18.3.11节）。请注意，支持leasequery[RFC5007]的服务器也需要记录此信息。
By sending Reconfigure messages, the server MAY initiate a configuration exchange to cause DHCP clients to obtain new addresses, prefixes, and other configuration information. For example, an administrator may use a server-initiated configuration exchange when links in the DHCP domain are to be renumbered or when other configuration options are updated, perhaps because servers are moved, added, or removed.
通过发送重新配置消息，服务器可以启动配置交换，以使DHCP客户端获得新地址、前缀和其他配置信息。例如，当DHCP域中的链接要重新编号或更新其他配置选项时，管理员可能会使用服务器启动的配置交换，这可能是因为服务器被移动、添加或删除。
When a client receives a Reconfigure message from the server, the client initiates sending a Renew, Rebind, or Information-request message as indicated by msg-type in the Reconfigure Message option (see Section 21.19). The server sends IAs and/or other configuration information to the client in a Reply message. The server MAY include options containing the IAs and new values for other configuration parameters in the Reply message, even if those IAs and parameters were not requested in the client's message.
当客户机从服务器接收到重新配置消息时，客户机启动发送续订、重新绑定或信息请求消息，如重新配置消息选项中的msg type所示（参见第21.19节）。服务器在回复消息中向客户端发送IAs和/或其他配置信息。服务器可能在回复消息中包含包含IAs和其他配置参数的新值的选项，即使这些IAs和参数未在客户端消息中请求。
See Section 18.4 for details regarding the handling of Solicit messages received via unicast. Unicast transmission of Solicit messages is not allowed, regardless of whether the Server Unicast option (see Section 21.12) is configured or not.
有关处理通过单播接收的请求消息的详细信息，请参见第18.4节。无论是否配置了服务器单播选项（见第21.12节），都不允许单播传输请求消息。
The server determines the information about the client and its location as described in Section 13 and checks its administrative policy about responding to the client. If the server is not
如第13节所述，服务器确定有关客户端及其位置的信息，并检查其有关响应客户端的管理策略。如果服务器不是
permitted to respond to the client, the server discards the Solicit message. For example, if the administrative policy for the server is that it may only respond to a client that is willing to accept a Reconfigure message, if the client does not include a Reconfigure Accept option (see Section 21.20) in the Solicit message, the server discards the Solicit message.
如果允许响应客户端，服务器将丢弃请求消息。例如，如果服务器的管理策略是，它可能只响应愿意接受重新配置消息的客户端，如果客户端在请求消息中不包括重新配置接受选项（参见第21.20节），则服务器将丢弃请求消息。
If (1) the server is permitted to respond to the client, (2) the client has not included a Rapid Commit option (see Section 21.14) in the Solicit message, or (3) the server has not been configured to respond with committed assignments of leases and other resources, the server sends an Advertise message to the client as described in Section 18.3.9.
如果（1）允许服务器响应客户端，（2）客户端未在请求消息中包含快速提交选项（见第21.14节），或（3）服务器未配置为响应租约和其他资源的提交分配，则服务器将按照第18.3.9节所述向客户端发送播发消息。
If the client has included a Rapid Commit option in the Solicit message and the server has been configured to respond with committed assignments of leases and other resources, the server responds to the Solicit with a Reply message. The server produces the Reply message as though it had received a Request message as described in Section 18.3.2. The server transmits the Reply message as described in Section 18.3.10. The server MUST commit the assignment of any addresses and delegated prefixes or other configuration information before sending a Reply message to a client. In this case, the server includes a Rapid Commit option in the Reply message to indicate that the Reply is in response to a Solicit message.
如果客户端已在请求消息中包含快速提交选项，并且服务器已配置为使用已提交的租约和其他资源分配进行响应，则服务器将使用回复消息响应请求。服务器生成回复消息，就好像它收到了第18.3.2节所述的请求消息一样。服务器按照第18.3.10节所述发送回复消息。在向客户端发送回复消息之前，服务器必须提交任何地址和委派前缀或其他配置信息的分配。在这种情况下，服务器在回复消息中包括快速提交选项，以指示回复是对请求消息的响应。
DISCUSSION:
讨论：
When using the Solicit/Reply message exchange, the server commits the assignment of any leases before sending the Reply message. The client can assume that it has been assigned the leases in the Reply message and does not need to send a Request message for those leases.
使用请求/回复消息交换时，服务器在发送回复消息之前提交任何租约的分配。客户机可以假定已在回复消息中为其分配了租约，并且不需要为这些租约发送请求消息。
Typically, servers that are configured to use the Solicit/Reply message exchange will be deployed so that only one server will respond to a Solicit message. If more than one server responds, the client will only use the leases from one of the servers, while the leases from the other servers will be committed to the client but not used by the client.
通常，将部署配置为使用请求/回复消息交换的服务器，以便只有一台服务器响应请求消息。如果有多个服务器响应，客户端将只使用其中一个服务器的租约，而来自其他服务器的租约将提交给客户端，但客户端不使用。
See Section 18.4 for details regarding the handling of Request messages received via unicast.
有关处理通过单播接收的请求消息的详细信息，请参见第18.4节。
When the server receives a valid Request message, the server creates the bindings for that client according to the server's policy and configuration information and records the IAs and other information requested by the client.
当服务器收到有效的请求消息时，服务器将根据服务器的策略和配置信息为该客户端创建绑定，并记录客户端请求的IAs和其他信息。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Request message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从请求消息复制到“transaction ID”字段中来构造一条回复消息。
The server MUST include in the Reply message a Server Identifier option (see Section 21.3) containing the server's DUID and the Client Identifier option (see Section 21.2) from the Request message.
服务器必须在回复消息中包含包含服务器DUID的服务器标识符选项（见第21.3节）和请求消息中的客户端标识符选项（见第21.2节）。
The server examines all IAs in the message from the client.
服务器检查来自客户端的消息中的所有IAs。
For each IA_NA option (see Section 21.4) and IA_TA option (see Section 21.5) in the Request message, the server checks if the prefixes of included addresses are appropriate for the link to which the client is connected. If any of the prefixes of the included addresses are not appropriate for the link to which the client is connected, the server MUST return the IA to the client with a Status Code option (see Section 21.13) with the value NotOnLink. If the server does not send the NotOnLink status code but it cannot assign any IP addresses to an IA, the server MUST return the IA option in the Reply message with no addresses in the IA and a Status Code option containing status code NoAddrsAvail in the IA.
对于请求消息中的每个IA_-NA选项（请参见第21.4节）和IA_-TA选项（请参见第21.5节），服务器将检查所包含地址的前缀是否适用于客户端所连接的链接。如果所包含地址的任何前缀不适用于客户机连接到的链接，则服务器必须向客户机返回IA，并带有值为NotOnLink的状态代码选项（参见第21.13节）。如果服务器未发送NotOnLink状态代码，但无法将任何IP地址分配给IA，则服务器必须在IA中返回回复消息中的IA选项（IA中没有地址），并在IA中返回包含状态代码NOADRSAVAIL的状态代码选项。
For any IA_PD option (see Section 21.21) in the Request message to which the server cannot assign any delegated prefixes, the server MUST return the IA_PD option in the Reply message with no prefixes in the IA_PD and with a Status Code option containing status code NoPrefixAvail in the IA_PD.
对于请求消息中的任何IA_PD选项（参见第21.21节），如果服务器无法为其分配任何委派前缀，则服务器必须在回复消息中返回IA_PD选项，且IA_PD中不带前缀，且带有包含IA_PD中状态代码NoPrefixAvail的状态代码选项。
The server MAY assign different addresses and/or delegated prefixes to an IA than those included within the IA of the client's Request message.
服务器可以向IA分配不同于客户端请求消息的IA中包含的地址和/或委派前缀。
For all IAs to which the server can assign addresses or delegated prefixes, the server includes the IAs with addresses (for IA_NAs and IA_TAs), prefixes (for IA_PDs), and other configuration parameters and records the IA as a new client binding. The server MUST NOT include any addresses or delegated prefixes in the IA that the server does not assign to the client.
对于服务器可以分配地址或委派前缀的所有IAs，服务器包括带有地址（用于IA_NAs和IA_TA）、前缀（用于IA_PDs）和其他配置参数的IAs，并将IA记录为新的客户端绑定。服务器不得在IA中包含服务器未分配给客户端的任何地址或委派前缀。
The T1/T2 times set in each applicable IA option for a Reply MUST be the same values across all IAs. The server MUST determine the T1/T2 times across all of the applicable client's bindings in the Reply. This facilitates the client being able to renew all of the bindings at the same time.
在每个适用的IA选项中为回复设置的T1/T2时间在所有IA中必须是相同的值。服务器必须在应答中确定所有适用客户端绑定的T1/T2时间。这使客户端能够同时更新所有绑定。
The server SHOULD include a Reconfigure Accept option (see Section 21.20) if the server policy enables the reconfigure mechanism and the client supports it. Currently, sending this option in a Reply is technically redundant, as the use of the reconfiguration mechanism requires authentication; at present, the only defined mechanism is RKAP (see Section 20.4), and the presence of the reconfigure key signals support for the acceptance of Reconfigure messages. However, there may be better security mechanisms defined in the future that would cause RKAP to not be used anymore.
如果服务器策略启用重新配置机制且客户端支持，则服务器应包括重新配置接受选项（请参阅第21.20节）。目前，在回复中发送此选项在技术上是多余的，因为使用重新配置机制需要身份验证；目前，唯一定义的机制是RKAP（见第20.4节），且重新配置密钥信号的存在支持接受重新配置消息。但是，将来可能会定义更好的安全机制，这将导致不再使用RKAP。
The server includes other options containing configuration information to be returned to the client as described in Section 18.3.
如第18.3节所述，服务器包括包含要返回给客户端的配置信息的其他选项。
If the server finds that the client has included an IA in the Request message for which the server already has a binding that associates the IA with the client, the server sends a Reply message with existing bindings, possibly with updated lifetimes. The server may update the bindings according to its local policies, but the server SHOULD generate the response again and not simply retransmit previously sent information, even if the "transaction-id" field value matches a previous transmission. The server MUST NOT cache its responses.
如果服务器发现客户机已在请求消息中包含IA，而服务器已为该请求消息创建了将IA与客户机关联的绑定，则服务器将发送一条带有现有绑定的回复消息，该绑定可能具有更新的生存期。服务器可以根据其本地策略更新绑定，但服务器应该再次生成响应，而不是简单地重新传输以前发送的信息，即使“事务id”字段值与以前的传输匹配。服务器不能缓存其响应。
DISCUSSION:
讨论：
Cached replies are bad because lifetimes need to be updated (either decrease the timers by the amount of time elapsed since the original transmission or keep the lifetime values and update the lease information in the server's database). Also, if the message uses any security protection (such as the Replay Detection Method (RDM), as described in Section 20.3), its value must be updated. Additionally, any digests must be updated. Given all of the above, caching replies is far more complex than simply sending the same buffer as before, and it is easy to miss some of those steps.
缓存的回复是错误的，因为需要更新生存期（或者将计时器减少自原始传输以来经过的时间量，或者保留生存期值并更新服务器数据库中的租约信息）。此外，如果消息使用任何安全保护（如第20.3节所述的重播检测方法（RDM）），则必须更新其值。此外，任何摘要都必须更新。考虑到以上所有因素，缓存回复远比像以前那样简单地发送相同的缓冲区复杂，而且很容易错过其中一些步骤。
See Section 18.4 for details regarding the handling of Confirm messages received via unicast. Unicast transmission of Confirm messages is not allowed, regardless of whether the Server Unicast option (see Section 21.12) is configured or not.
有关处理通过单播接收的确认消息的详细信息，请参见第18.4节。无论是否配置了服务器单播选项（见第21.12节），都不允许单播传输确认消息。
When the server receives a Confirm message, the server determines whether the addresses in the Confirm message are appropriate for the link to which the client is attached. If all of the addresses in the Confirm message pass this test, the server returns a status of Success. If any of the addresses do not pass this test, the server returns a status of NotOnLink. If the server is unable to perform this test (for example, the server does not have information about prefixes on the link to which the client is connected) or there were no addresses in any of the IAs sent by the client, the server MUST NOT send a Reply to the client.
当服务器收到确认消息时，服务器将确定确认消息中的地址是否适合客户端所连接的链接。如果确认消息中的所有地址都通过了此测试，服务器将返回成功状态。如果任何地址未通过此测试，服务器将返回NotOnLink状态。如果服务器无法执行此测试（例如，服务器没有有关客户端连接到的链接上的前缀的信息），或者客户端发送的任何IAs中没有地址，则服务器不得向客户端发送回复。
The server ignores the T1 and T2 fields in the IA options and the preferred-lifetime and valid-lifetime fields in the IA Address options (see Section 21.6).
服务器忽略IA选项中的T1和T2字段以及IA地址选项中的首选生存期和有效生存期字段（参见第21.6节）。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Confirm message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从确认消息复制到“transaction ID”字段中来构造回复消息。
The server MUST include in the Reply message a Server Identifier option (see Section 21.3) containing the server's DUID and the Client Identifier option (see Section 21.2) from the Confirm message. The server includes a Status Code option (see Section 21.13) indicating the status of the Confirm message.
服务器必须在回复消息中包含包含服务器DUID的服务器标识符选项（见第21.3节）和确认消息中的客户端标识符选项（见第21.2节）。服务器包括一个状态代码选项（见第21.13节），指示确认消息的状态。
See Section 18.4 for details regarding the handling of Renew messages received via unicast.
有关处理通过单播接收的续订消息的详细信息，请参见第18.4节。
For each IA in the Renew message from a client, the server locates the client's binding and verifies that the information in the IA from the client matches the information stored for that client.
对于来自客户端的续订消息中的每个IA，服务器将定位客户端的绑定，并验证来自客户端的IA中的信息是否与为该客户端存储的信息匹配。
If the server finds the client entry for the IA, the server sends the IA back to the client with new lifetimes and, if applicable, T1/T2 times. If the server is unable to extend the lifetimes of an address or delegated prefix in the IA, the server MAY choose not to include the IA Address option (see Section 21.6) for that address or IA Prefix option (see Section 21.22) for that delegated prefix. If the server chooses to include the IA Address or IA Prefix option for such
如果服务器找到IA的客户机条目，则服务器将IA发送回客户机，并提供新的生存期，如果适用，还包括T1/T2时间。如果服务器无法延长IA中地址或委派前缀的生存期，则服务器可以选择不包括该地址的IA地址选项（见第21.6节）或该委派前缀的IA前缀选项（见第21.22节）。如果服务器选择将IA地址或IA前缀选项包含在
an address or delegated prefix, the server SHOULD set T1 and T2 values to the valid lifetime for the IA option unless the server also includes other addresses or delegated prefixes that the server is able to extend for the IA. Setting T1 and T2 to values equal to the valid lifetime informs the client that the leases associated with said IA will not be extended, so there is no point in trying. Also, it avoids generating unnecessary traffic as the remaining lifetime approaches 0.
对于地址或委派前缀，服务器应将T1和T2值设置为IA选项的有效生存期，除非服务器还包括服务器能够为IA扩展的其他地址或委派前缀。将T1和T2设置为等于有效生存期的值会通知客户端与所述IA关联的租约将不会延长，因此尝试没有意义。此外，它还可以避免在剩余生存期接近0时生成不必要的通信量。
The server may choose to change the list of addresses or delegated prefixes and the lifetimes in IAs that are returned to the client.
服务器可以选择更改返回给客户端的地址或委派前缀列表以及IAs中的生存期。
If the server finds that any of the addresses in the IA are not appropriate for the link to which the client is attached, the server returns the address to the client with lifetimes of 0.
如果服务器发现IA中的任何地址不适合客户端连接到的链接，则服务器将地址返回给客户端，其生存期为0。
If the server finds that any of the delegated prefixes in the IA are not appropriate for the link to which the client is attached, the server returns the delegated prefix to the client with lifetimes of 0.
如果服务器发现IA中的任何委派前缀不适用于客户端连接到的链接，则服务器将委派前缀返回给客户端，其生存期为0。
For each IA for which the server cannot find a client entry, the server has the following choices, depending on the server's policy and configuration information:
对于服务器找不到客户端条目的每个IA，服务器有以下选择，具体取决于服务器的策略和配置信息：
- If the server is configured to create new bindings as a result of processing Renew messages, the server SHOULD create a binding and return the IA with assigned addresses or delegated prefixes with lifetimes and, if applicable, T1/T2 times and other information requested by the client. If the client included the IA Prefix option within the IA_PD option (see Section 21.21) with a zero value in the "IPv6-prefix" field and a non-zero value in the "prefix-length" field, the server MAY use the "prefix-length" value as a hint for the length of the prefixes to be assigned (see [RFC8168] for further details on prefix-length hints).
- 如果服务器配置为在处理续订消息后创建新绑定，则服务器应创建绑定并返回IA，其中包含分配的地址或具有生命周期的委派前缀，以及T1/T2时间（如果适用）和客户端请求的其他信息。如果客户端将IA前缀选项包含在IA_PD选项中（参见第21.21节），“IPv6前缀”字段中为零值，“前缀长度”字段中为非零值，则服务器可以使用“前缀长度”值作为要分配前缀长度的提示（有关前缀长度提示的更多详细信息，请参见[RFC8168]）。
- If the server is configured to create new bindings as a result of processing Renew messages but the server will not assign any leases to an IA, the server returns the IA option containing a Status Code option (see Section 21.13) with the NoAddrsAvail or NoPrefixAvail status code and a status message for a user.
- 如果服务器配置为在处理续订消息后创建新绑定，但服务器不会将任何租约分配给IA，则服务器将返回IA选项，该选项包含状态代码选项（请参阅第21.13节），其中包含NOADRSAVAIL或NoPrefixAvail状态代码以及用户的状态消息。
- If the server does not support creation of new bindings for the client sending a Renew message or if this behavior is disabled according to the server's policy or configuration information, the server returns the IA option containing a Status Code option with the NoBinding status code and a status message for a user.
- 如果服务器不支持为发送续订消息的客户端创建新绑定，或者根据服务器的策略或配置信息禁用了此行为，则服务器将返回IA选项，该选项包含一个状态代码选项，其中包含NoBinding Status Code和一条用户状态消息。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Renew message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从续订消息复制到“transaction ID”字段中来构造回复消息。
The server MUST include in the Reply message a Server Identifier option (see Section 21.3) containing the server's DUID and the Client Identifier option (see Section 21.2) from the Renew message.
服务器必须在回复消息中包含包含服务器DUID的服务器标识符选项（见第21.3节）和续订消息中的客户端标识符选项（见第21.2节）。
The server includes other options containing configuration information to be returned to the client as described in Section 18.3.
如第18.3节所述，服务器包括包含要返回给客户端的配置信息的其他选项。
The server MAY include options containing the IAs and values for other configuration parameters, even if those parameters were not requested in the Renew message.
服务器可能包括包含IAs和其他配置参数值的选项，即使在续订消息中未请求这些参数。
The T1/T2 values set in each applicable IA option for a Reply MUST be the same across all IAs. The server MUST determine the T1/T2 values across all of the applicable client's bindings in the Reply. This facilitates the client being able to renew all of the bindings at the same time.
回复的每个适用IA选项中设置的T1/T2值在所有IA中必须相同。服务器必须在应答中确定所有适用客户端绑定的T1/T2值。这使客户端能够同时更新所有绑定。
See Section 18.4 for details regarding the handling of Rebind messages received via unicast. Unicast transmission of Rebind messages is not allowed, regardless of whether the Server Unicast option (see Section 21.12) is configured or not.
有关处理通过单播接收的重新绑定消息的详细信息，请参见第18.4节。无论是否配置了服务器单播选项（见第21.12节），都不允许重新绑定消息的单播传输。
When the server receives a Rebind message that contains an IA option from a client, it locates the client's binding and verifies that the information in the IA from the client matches the information stored for that client.
当服务器从客户端接收到包含IA选项的重新绑定消息时，它将定位客户端的绑定，并验证来自客户端的IA中的信息是否与为该客户端存储的信息匹配。
If the server finds the client entry for the IA and the server determines that the addresses or delegated prefixes in the IA are appropriate for the link to which the client's interface is attached according to the server's explicit configuration information, the server SHOULD send the IA back to the client with new lifetimes and, if applicable, T1/T2 values. If the server is unable to extend the lifetimes of an address in the IA, the server MAY choose not to include the IA Address option (see Section 21.6) for this address. If the server is unable to extend the lifetimes of a delegated prefix in the IA, the server MAY choose not to include the IA Prefix option (see Section 21.22) for this prefix.
如果服务器找到IA的客户端条目，并且服务器根据服务器的显式配置信息确定IA中的地址或委派前缀适用于客户端接口连接到的链接，则服务器应将IA发送回具有新生存期的客户端，如果适用，T1/T2值。如果服务器无法延长IA中地址的生存期，则服务器可以选择不包括该地址的IA地址选项（参见第21.6节）。如果服务器无法延长IA中委派前缀的生存期，则服务器可以选择不包括该前缀的IA前缀选项（参见第21.22节）。
If the server finds that the client entry for the IA and any of the addresses or delegated prefixes are no longer appropriate for the link to which the client's interface is attached according to the server's explicit configuration information, the server returns those addresses or delegated prefixes to the client with lifetimes of 0.
如果服务器根据服务器的显式配置信息发现IA的客户端条目和任何地址或委派前缀不再适用于客户端接口所连接到的链接，则服务器会将这些地址或委派前缀返回给客户端，其生存期为0。
If the server cannot find a client entry for the IA, the server checks if the IA contains addresses (for IA_NAs and IA_TAs) or delegated prefixes (for IA_PDs). The server checks if the addresses and delegated prefixes are appropriate for the link to which the client's interface is attached according to the server's explicit configuration information. For any address that is not appropriate for the link to which the client's interface is attached, the server MAY include the IA Address option with lifetimes of 0. For any delegated prefix that is not appropriate for the link to which the client's interface is attached, the server MAY include the IA Prefix option with lifetimes of 0. The Reply with lifetimes of 0 constitutes an explicit notification to the client that the specific addresses and delegated prefixes are no longer valid and MUST NOT be used by the client. If the server chooses to not include any IAs containing IA Address or IA Prefix options with lifetimes of 0 and the server does not include any other IAs with leases and/or status codes, the server does not send a Reply message. In this situation, the server discards the Rebind message.
如果服务器找不到IA的客户端条目，服务器将检查IA是否包含地址（对于IA_NAs和IA_TA）或委派前缀（对于IA_PD）。服务器根据服务器的显式配置信息检查地址和委派前缀是否适合客户端接口所连接的链接。对于任何不适合客户端接口连接到的链接的地址，服务器可能会包括IA address选项，其生存期为0。对于任何不适用于客户端接口所连接的链接的委托前缀，服务器可能会包括生命周期为0的IA prefix选项。生存期为0的回复构成对客户端的明确通知，即特定地址和委派前缀不再有效，客户端不得使用。如果服务器选择不包括任何包含IA地址或IA前缀选项且生存期为0的IAs，并且服务器不包括任何其他具有租约和/或状态代码的IAs，则服务器不会发送回复消息。在这种情况下，服务器将丢弃重新绑定消息。
Otherwise, for each IA for which the server cannot find a client entry, the server has the following choices, depending on the server's policy and configuration information:
否则，对于服务器找不到客户端条目的每个IA，服务器有以下选择，具体取决于服务器的策略和配置信息：
- If the server is configured to create new bindings as a result of processing Rebind messages (also see the note below about the Rapid Commit option (Section 21.14)), the server SHOULD create a binding and return the IA with allocated leases with lifetimes and, if applicable, T1/T2 values and other information requested by the client. The server MUST NOT return any addresses or delegated prefixes in the IA that the server does not assign to the client.
- 如果服务器被配置为通过处理重新绑定消息来创建新绑定（另请参见下面关于快速提交选项的说明（第21.14节）），则服务器应创建绑定并返回IA，其中包含分配的租约和生存期，如果适用，还包括T1/T2值以及客户端请求的其他信息。服务器不得返回IA中服务器未分配给客户端的任何地址或委派前缀。
- If the server is configured to create new bindings as a result of processing Rebind messages but the server will not assign any leases to an IA, the server returns the IA option containing a Status Code option (see Section 21.13) with the NoAddrsAvail or NoPrefixAvail status code and a status message for a user.
- 如果服务器配置为在处理重新绑定消息后创建新绑定，但服务器不会将任何租约分配给IA，则服务器将返回IA选项，该选项包含状态代码选项（请参阅第21.13节），其中包含NOADRSAVAIL或NoPrefixAvail状态代码以及用户的状态消息。
- If the server does not support creation of new bindings for the client sending a Rebind message or if this behavior is disabled according to the server's policy or configuration information, the server returns the IA option containing a Status Code option with the NoBinding status code and a status message for a user.
- 如果服务器不支持为发送重新绑定消息的客户端创建新绑定，或者根据服务器的策略或配置信息禁用了此行为，则服务器将返回IA选项，该选项包含一个状态代码选项，其中包含NoBinding Status Code和一条用户状态消息。
When the server creates new bindings for the IA, it is possible that other servers also create bindings as a result of receiving the same Rebind message; see the "DISCUSSION" text in Section 21.14. Therefore, the server SHOULD only create new bindings during processing of a Rebind message if the server is configured to respond with a Reply message to a Solicit message containing the Rapid Commit option.
当服务器为IA创建新绑定时，其他服务器也可能由于接收到相同的重新绑定消息而创建绑定；见第21.14节中的“讨论”文本。因此，如果服务器配置为使用回复消息响应包含快速提交选项的请求消息，则服务器仅应在处理重新绑定消息期间创建新绑定。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Rebind message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从重新绑定消息复制到“transaction ID”字段中来构造一条回复消息。
The server MUST include in the Reply message a Server Identifier option (see Section 21.3) containing the server's DUID and the Client Identifier option (see Section 21.2) from the Rebind message.
服务器必须在回复消息中包含包含服务器DUID的服务器标识符选项（见第21.3节）和来自重新绑定消息的客户端标识符选项（见第21.2节）。
The server includes other options containing configuration information to be returned to the client as described in Section 18.3.
如第18.3节所述，服务器包括包含要返回给客户端的配置信息的其他选项。
The server MAY include options containing the IAs and values for other configuration parameters, even if those IAs and parameters were not requested in the Rebind message.
服务器可能包括包含IAs和其他配置参数值的选项，即使在重新绑定消息中未请求这些IAs和参数。
The T1 or T2 values set in each applicable IA option for a Reply MUST be the same values across all IAs. The server MUST determine the T1 or T2 values across all of the applicable client's bindings in the Reply. This facilitates the client being able to renew all of the bindings at the same time.
回复的每个适用IA选项中设置的T1或T2值在所有IA中必须是相同的值。服务器必须在应答中确定所有适用客户端绑定的T1或T2值。这使客户端能够同时更新所有绑定。
See Section 18.4 for details regarding the handling of Information-request messages received via unicast.
有关处理通过单播接收的信息请求消息的详细信息，请参见第18.4节。
When the server receives an Information-request message, the client is requesting configuration information that does not include the assignment of any leases. The server determines all configuration parameters appropriate to the client, based on the server configuration policies known to the server.
当服务器收到信息请求消息时，客户端请求的配置信息不包括任何租约的分配。服务器根据服务器已知的服务器配置策略确定适合客户端的所有配置参数。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Information-request message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从信息请求消息复制到“transaction ID”字段中来构造一条回复消息。
The server MUST include a Server Identifier option (see Section 21.3) containing the server's DUID in the Reply message. If the client included a Client Identifier option (see Section 21.2) in the Information-request message, the server copies that option to the Reply message.
服务器必须在回复消息中包含包含服务器DUID的服务器标识符选项（见第21.3节）。如果客户机在信息请求消息中包含客户机标识符选项（参见第21.2节），则服务器会将该选项复制到回复消息中。
The server includes options containing configuration information to be returned to the client as described in Section 18.3. The server MAY include additional options that were not requested by the client in the Information-request message.
如第18.3节所述，服务器包括包含要返回给客户端的配置信息的选项。服务器可能在信息请求消息中包含客户端未请求的其他选项。
If the Information-request message received from the client did not include a Client Identifier option, the server SHOULD respond with a Reply message containing any configuration parameters that are not determined by the client's identity. If the server chooses not to respond, the client may continue to retransmit the Information-request message indefinitely.
如果从客户端接收到的信息请求消息不包括客户端标识符选项，则服务器应使用包含未由客户端标识确定的任何配置参数的回复消息进行响应。如果服务器选择不响应，客户端可能会继续无限期地重新传输信息请求消息。
See Section 18.4 for details regarding the handling of Release messages received via unicast.
有关处理通过单播接收的发布消息的详细信息，请参见第18.4节。
The server constructs a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Release message into the "transaction-id" field.
服务器通过将“msg type”字段设置为Reply并将事务ID从发布消息复制到“transaction ID”字段中来构造一条回复消息。
Upon the receipt of a valid Release message, the server examines the IAs and the leases in the IAs for validity. If the IAs in the message are in a binding for the client and the leases in the IAs have been assigned by the server to those IAs, the server deletes the leases from the IAs and makes the leases available for assignment to other clients. The server ignores leases not assigned to the IAs, although it may choose to log an error.
在收到有效的发布消息后，服务器将检查IAs和IAs中的租约的有效性。如果消息中的IAs处于客户端的绑定中，并且服务器已将IAs中的租约分配给这些IAs，则服务器将从IAs中删除租约，并使租约可用于分配给其他客户端。服务器会忽略未分配给IAs的租约，尽管它可能会选择记录错误。
After all the leases have been processed, the server generates a Reply message and includes a Status Code option (see Section 21.13) with the value Success, a Server Identifier option (see Section 21.3) with the server's DUID, and a Client Identifier option (see Section 21.2) with the client's DUID. For each IA in the Release message for which the server has no binding information, the server adds an IA option using the IAID from the Release message and includes a Status Code option with the value NoBinding in the IA option. No other options are included in the IA option.
处理完所有租约后，服务器将生成一条回复消息，并包括一个值为Success的状态代码选项（参见第21.13节）、一个带有服务器DUID的服务器标识符选项（参见第21.3节）和一个带有客户端DUID的客户端标识符选项（参见第21.2节）。对于服务器没有绑定信息的发布消息中的每个IA，服务器使用发布消息中的IAID添加一个IA选项，并在IA选项中包含一个值为NoBinding的状态代码选项。IA选项中不包括其他选项。
A server may choose to retain a record of assigned leases and IAs after the lifetimes on the leases have expired to allow the server to reassign the previously assigned leases to a client.
服务器可以选择在租约的生存期到期后保留已分配租约和IAs的记录，以允许服务器将以前分配的租约重新分配给客户端。
See Section 18.4 for details regarding the handling of Decline messages received via unicast.
有关处理通过单播接收的拒绝消息的详细信息，请参见第18.4节。
Upon the receipt of a valid Decline message, the server examines the IAs and the addresses in the IAs for validity. If the IAs in the message are in a binding for the client and the addresses in the IAs have been assigned by the server to those IAs, the server deletes the addresses from the IAs. The server ignores addresses not assigned to the IAs (though it may choose to log an error if it finds such addresses).
在收到有效的拒绝消息后，服务器将检查IAs和IAs中的地址的有效性。如果消息中的IAs位于客户端的绑定中，并且服务器已将IAs中的地址分配给这些IAs，则服务器将从IAs中删除这些地址。服务器忽略未分配给IAs的地址（但如果找到此类地址，则可能会选择记录错误）。
The client has found any addresses in the Decline messages to be already in use on its link. Therefore, the server SHOULD mark the addresses declined by the client so that those addresses are not assigned to other clients and MAY choose to make a notification that addresses were declined. Local policy on the server determines when the addresses identified in a Decline message may be made available for assignment.
客户端发现拒绝消息中的任何地址已在其链接上使用。因此，服务器应该标记客户端拒绝的地址，以便这些地址不会分配给其他客户端，并且可以选择发出地址被拒绝的通知。服务器上的本地策略确定拒绝消息中标识的地址何时可用于分配。
After all the addresses have been processed, the server generates a Reply message by setting the "msg-type" field to REPLY and copying the transaction ID from the Decline message into the "transaction-id" field. The client includes a Status Code option (see Section 21.13) with the value Success, a Server Identifier option (see Section 21.3) with the server's DUID, and a Client Identifier option (see Section 21.2) with the client's DUID. For each IA in the Decline message for which the server has no binding information, the server adds an IA option using the IAID from the Decline message and includes a Status Code option with the value NoBinding in the IA option. No other options are included in the IA option.
处理完所有地址后，服务器通过将“msg type”字段设置为Reply并将事务ID从拒绝消息复制到“transaction ID”字段来生成一条回复消息。客户机包括一个值为Success的状态代码选项（参见第21.13节）、一个值为Success的服务器标识符选项（参见第21.3节）和一个值为Success的客户机标识符选项（参见第21.2节）。对于服务器没有绑定信息的拒绝消息中的每个IA，服务器使用拒绝消息中的IAID添加一个IA选项，并在IA选项中包含一个值为NoBinding的状态代码选项。IA选项中不包括其他选项。
The server sets the "msg-type" field to ADVERTISE and copies the contents of the "transaction-id" field from the Solicit message received from the client to the Advertise message. The server includes its server identifier in a Server Identifier option (see Section 21.3) and copies the Client Identifier option (see Section 21.2) from the Solicit message into the Advertise message.
服务器将“msg type”字段设置为播发，并将“transaction id”字段的内容从从客户端接收的请求消息复制到播发消息。服务器在服务器标识符选项（见第21.3节）中包含其服务器标识符，并将客户标识符选项（见第21.2节）从请求消息复制到播发消息中。
The server MAY add a Preference option (see Section 21.8) to carry the preference value for the Advertise message. The server implementation SHOULD allow the setting of a server preference value by the administrator. The server preference value MUST default to 0 unless otherwise configured by the server administrator.
服务器可以添加首选项（见第21.8节），以携带广告消息的首选项值。服务器实现应允许管理员设置服务器首选项值。除非服务器管理员另有配置，否则服务器首选项值必须默认为0。
The server includes a Reconfigure Accept option (see Section 21.20) if the server wants to indicate that it supports the Reconfigure mechanism. This information may be used by the client during the server selection process.
如果服务器希望表明其支持重新配置机制，则服务器包括重新配置接受选项（参见第21.20节）。客户机可以在服务器选择过程中使用此信息。
The server includes the options the server will return to the client in a subsequent Reply message. The information in these options may be used by the client in the selection of a server if the client receives more than one Advertise message. The server MUST include options in the Advertise message containing configuration parameters for all of the options identified in the Option Request option (see Section 21.7) in the Solicit message that the server has been configured to return to the client. If the Option Request option includes a container option, the server MUST include all the options that are eligible to be encapsulated in the container. The Option Request option MAY be used to signal support for a feature even when that option is encapsulated, as in the case of the Prefix Exclude option [RFC6603]. In this case, special processing is required by the server. The server MAY return additional options to the client if it has been configured to do so.
服务器包括服务器将在后续回复消息中返回给客户端的选项。如果客户机接收到多个播发消息，则客户机可以在选择服务器时使用这些选项中的信息。服务器必须在播发消息中包含选项，该消息包含请求消息中选项请求选项（见第21.7节）中标识的所有选项的配置参数，该请求消息已将服务器配置为返回客户端。如果选项请求选项包括容器选项，则服务器必须包括符合条件可封装在容器中的所有选项。选项请求选项可用于表示对功能的支持，即使该选项已封装，如前缀排除选项[RFC6603]的情况。在这种情况下，服务器需要进行特殊处理。如果已将服务器配置为向客户端返回其他选项，则服务器可能会向客户端返回这些选项。
The server MUST include IA options in the Advertise message containing any addresses and/or delegated prefixes that would be assigned to IAs contained in the Solicit message from the client. If the client has included addresses in the IA Address options (see Section 21.6) in the Solicit message, the server MAY use those addresses as hints about the addresses that the client would like to receive. If the client has included IA Prefix options (see Section 21.22), the server MAY use the prefix contained in the "IPv6-prefix" field and/or the prefix length contained in the "prefix-length" field as hints about the prefixes the client would like to receive. If the server is not going to assign an address or delegated prefix received as a hint in the Solicit message, the server MUST NOT include this address or delegated prefix in the Advertise message.
服务器必须在包含任何地址和/或委派前缀的播发消息中包含IA选项，这些地址和/或委派前缀将分配给客户端请求消息中包含的IAs。如果客户机在请求消息中的IA地址选项（见第21.6节）中包含了地址，则服务器可以使用这些地址作为客户机希望接收的地址的提示。如果客户端包含IA前缀选项（参见第21.22节），则服务器可以使用“IPv6前缀”字段中包含的前缀和/或“前缀长度”字段中包含的前缀长度作为客户端希望接收的前缀的提示。如果服务器不打算分配在请求消息中作为提示接收的地址或委派前缀，则服务器不得在播发消息中包含此地址或委派前缀。
If the server will not assign any addresses to an IA_NA or IA_TA in subsequent Request messages from the client, the server MUST include the IA option in the Advertise message with no addresses in that IA and a Status Code option (see Section 21.13) encapsulated in the IA option containing status code NoAddrsAvail.
如果服务器不会在来自客户端的后续请求消息中为IA_NA或IA_TA分配任何地址，则服务器必须在播发消息中包含IA选项（该IA中没有地址），并在包含状态代码NoAddrsAvail的IA选项中封装状态代码选项（见第21.13节）。
If the server will not assign any prefixes to an IA_PD in subsequent Request messages from the client, the server MUST include the IA_PD option (see Section 21.21) in the Advertise message with no prefixes in the IA_PD option and a Status Code option encapsulated in the IA_PD containing status code NoPrefixAvail.
如果服务器不会在来自客户端的后续请求消息中为IA_PD分配任何前缀，则服务器必须在播发消息中包含IA_PD选项（参见第21.21节），且IA_PD选项中没有前缀，并且IA_PD中封装的状态代码选项包含状态代码NoPrefixAvail。
Transmission of Advertise messages is described in the next section.
下一节将介绍播发消息的传输。
If the original message was received directly by the server, the server unicasts the Advertise or Reply message directly to the client using the address in the source address field from the IP datagram in which the original message was received. The Advertise or Reply message MUST be unicast through the interface on which the original message was received.
如果原始消息由服务器直接接收，则服务器使用接收原始消息的IP数据报的源地址字段中的地址将播发或回复消息直接单播到客户端。播发或回复消息必须通过接收原始消息的接口单播。
If the original message was received in a Relay-forward message, the server constructs a Relay-reply message with the Reply message in the payload of a Relay Message option (see Section 21.10). If the Relay-forward messages included an Interface-Id option (see Section 21.18), the server copies that option to the Relay-reply message. The server unicasts the Relay-reply message directly to the relay agent using the address in the source address field from the IP datagram in which the Relay-forward message was received. See Section 19.3 for more details on the construction of Relay-reply messages.
如果在中继转发消息中接收到原始消息，则服务器将在中继消息选项的有效负载中构造一条中继回复消息（请参阅第21.10节）。如果中继转发消息包含接口Id选项（参见第21.18节），服务器将该选项复制到中继回复消息。服务器使用从接收中继转发消息的IP数据报的源地址字段中的地址，将中继回复消息直接单播到中继代理。有关中继回复消息构造的更多详细信息，请参见第19.3节。
The server sets the "msg-type" field to RECONFIGURE and sets the "transaction-id" field to 0. The server includes a Server Identifier option (see Section 21.3) containing its DUID and a Client Identifier option (see Section 21.2) containing the client's DUID in the Reconfigure message.
服务器将“msg type”字段设置为重新配置，并将“transaction id”字段设置为0。服务器包括一个包含其DUID的服务器标识符选项（见第21.3节）和一个包含重新配置消息中的客户端DUID的客户端标识符选项（见第21.2节）。
Because of the risk of denial-of-service (DoS) attacks against DHCP clients, the use of a security mechanism is mandated in Reconfigure messages. The server MUST use DHCP authentication in the Reconfigure message (see Section 20.4).
由于存在针对DHCP客户端的拒绝服务（DoS）攻击风险，因此在重新配置消息时必须使用安全机制。服务器必须在重新配置消息中使用DHCP身份验证（请参阅第20.4节）。
The server MUST include a Reconfigure Message option (see Section 21.19) to select whether the client responds with a Renew message, a Rebind message, or an Information-request message.
服务器必须包括一个重新配置消息选项（见第21.19节），以选择客户端是以续订消息、重新绑定消息还是信息请求消息进行响应。
The server MUST NOT include any other options in the Reconfigure message, except as specifically allowed in the definition of individual options.
服务器不得在重新配置消息中包含任何其他选项，除非在单个选项的定义中明确允许。
A server sends each Reconfigure message to a single DHCP client, using an IPv6 unicast address of sufficient scope belonging to the DHCP client. If the server does not have an address to which it can send the Reconfigure message directly to the client, the server uses a Relay-reply message (as described in Section 19.3) to send the Reconfigure message to a relay agent that will relay the message to the client. The server may obtain the address of the client (and the appropriate relay agent, if required) through the information the server has about clients that have been in contact with the server (see Section 18.3) or through some external agent.
服务器使用属于DHCP客户端的足够范围的IPv6单播地址将每个重新配置消息发送到单个DHCP客户端。如果服务器没有地址可将重新配置消息直接发送至客户端，则服务器使用中继回复消息（如第19.3节所述）将重新配置消息发送至中继代理，中继代理将消息中继至客户端。服务器可以通过服务器获得的有关与服务器接触的客户端的信息（参见第18.3节）或通过一些外部代理获取客户端（以及适当的中继代理，如果需要）的地址。
To reconfigure more than one client, the server unicasts a separate message to each client. The server may initiate the reconfiguration of multiple clients concurrently; for example, a server may send a Reconfigure message to additional clients while previous reconfiguration message exchanges are still in progress.
要重新配置多个客户端，服务器将向每个客户端单播一条单独的消息。服务器可同时启动多个客户端的重新配置；例如，当先前的重新配置消息交换仍在进行中时，服务器可能会向其他客户端发送重新配置消息。
The Reconfigure message causes the client to initiate a Renew/Reply, Rebind/Reply, or Information-request/Reply message exchange with the server. The server interprets the receipt of a Renew, Rebind, or Information-request message (whichever was specified in the original Reconfigure message) from the client as satisfying the Reconfigure message request.
重新配置消息导致客户端启动与服务器的续订/回复、重新绑定/回复或信息请求/回复消息交换。服务器将从客户端接收到续订、重新绑定或信息请求消息（以原始重新配置消息中指定的为准）解释为满足重新配置消息请求。
When transmitting the Reconfigure message, the server sets the retransmission time (RT) to REC_TIMEOUT. If the server does not receive a Renew, Rebind, or Information-request message from the client before the RT elapses, the server retransmits the Reconfigure message, doubles the RT value, and waits again. The server continues this process until REC_MAX_RC unsuccessful attempts have been made, at which point the server SHOULD abort the reconfigure process for that client.
传输重新配置消息时，服务器将重新传输时间（RT）设置为REC_TIMEOUT。如果服务器在RT过期之前未收到来自客户端的续订、重新绑定或信息请求消息，则服务器将重新传输重新配置消息，将RT值加倍，然后再次等待。服务器将继续此过程，直到尝试REC_MAX_RC失败，此时服务器应中止该客户端的重新配置过程。
Default and initial values for REC_TIMEOUT and REC_MAX_RC are documented in Section 7.6.
REC_TIMEOUT和REC_MAX_RC的默认值和初始值记录在第7.6节中。
Unless otherwise stated in the subsections of Section 18.3 that discuss the receipt of specific messages, the server is not supposed to accept unicast traffic when it is not explicitly configured to do so. For example, unicast transmission is not allowed for Solicit, Confirm, and Rebind messages (see Sections 18.3.1, 18.3.3, and 18.3.5, respectively), even if the Server Unicast option (see Section 21.12) is configured. For Request, Renew, Information-request, Release, and Decline messages, it is allowed only if the Server Unicast option is configured.
除非在第18.3节讨论特定消息接收的小节中另有说明，否则当服务器未明确配置为接受单播通信量时，不应接受单播通信量。例如，即使配置了服务器单播选项（参见第21.12节），请求、确认和重新绑定消息也不允许单播传输（分别参见第18.3.1、18.3.3和18.3.5节）。对于请求、续订、信息请求、发布和拒绝消息，仅当配置了服务器单播选项时才允许。
When the server receives a message via unicast from a client to which the server has not sent a Server Unicast option (or is not currently configured to do so), the server discards that message and responds with an Advertise (when responding to a Solicit message) or Reply message (when responding to any other messages) containing a Status Code option (see Section 21.13) with the value UseMulticast, a Server Identifier option (see Section 21.3) containing the server's DUID, the Client Identifier option (see Section 21.2) from the client message (if any), and no other options.
当服务器通过单播从未向其发送服务器单播选项（或当前未配置为发送服务器单播选项）的客户端接收到消息时，服务器将丢弃该消息，并使用播发（响应请求消息时）或回复消息（响应任何其他消息时）进行响应包含值为UseMocast的状态代码选项（见第21.13节）、包含服务器DUID的服务器标识符选项（见第21.3节）、来自客户端消息的客户端标识符选项（见第21.2节）（如有），并且没有其他选项。
The relay agent SHOULD be configured to use a list of destination addresses that includes unicast addresses. The list of destination addresses MAY include the All_DHCP_Servers multicast address or other addresses selected by the network administrator. If the relay agent has not been explicitly configured, it MUST use the All_DHCP_Servers multicast address as the default.
中继代理应配置为使用包含单播地址的目标地址列表。目标地址列表可以包括所有DHCP服务器多播地址或网络管理员选择的其他地址。如果中继代理尚未明确配置，则它必须使用All_DHCP_Servers多播地址作为默认地址。
If the relay agent relays messages to the All_DHCP_Servers multicast address or other multicast addresses, it sets the Hop Limit field to 8.
如果中继代理将消息中继到All_DHCP_服务器多播地址或其他多播地址，则会将跃点限制字段设置为8。
If the relay agent receives a message other than Relay-forward and Relay-reply and the relay agent does not recognize its message type, it MUST forward the message as described in Section 19.1.1.
如果中继代理接收到中继转发和中继回复以外的消息，且中继代理无法识别其消息类型，则必须按照第19.1.1节所述转发消息。
A relay agent relays both messages from clients and Relay-forward messages from other relay agents. When a relay agent receives a Relay-forward message, a recognized message type for which it is not the intended target, or an unrecognized message type [RFC7283], it constructs a new Relay-forward message. The relay agent copies the source address from the header of the IP datagram in which the message was received into the peer-address field of the Relay-forward message. The relay agent copies the received DHCP message (excluding any IP or UDP headers) into a Relay Message option (see Section 21.10) in the new message. The relay agent adds to the Relay-forward message any other options it is configured to include.
中继代理既中继来自客户端的消息，也中继转发来自其他中继代理的消息。当中继代理接收到中继转发消息、其不是预期目标的已识别消息类型或未识别消息类型[RFC7283]时，它将构造新的中继转发消息。中继代理将接收消息的IP数据报报头中的源地址复制到中继转发消息的对等地址字段中。中继代理将接收到的DHCP消息（不包括任何IP或UDP头）复制到新消息中的中继消息选项（参见第21.10节）中。中继代理将其配置为包括的任何其他选项添加到中继转发消息中。
[RFC6221] defines a Lightweight DHCPv6 Relay Agent (LDRA) that allows relay agent information to be inserted by an access node that performs a link-layer bridging (i.e., non-routing) function.
[RFC6221]定义了一个轻量级DHCPv6中继代理（LDRA），它允许执行链路层桥接（即非路由）功能的接入节点插入中继代理信息。
If the relay agent received the message to be relayed from a client, the relay agent places a globally scoped unicast address (i.e., GUA or ULA) from a prefix assigned to the link on which the client should be assigned leases into the link-address field. If such an address is not available, the relay agent may set the link-address field to a link-local address from the interface on which the original message was received. This is not recommended, as it may require that additional information be provided in the server configuration. See Section 3.2 of [RFC7969] for a detailed discussion.
如果中继代理从客户机接收到要中继的消息，则中继代理将一个全局范围的单播地址（即，GUA或ULA）从分配给应分配客户机的链路的前缀放入链路地址字段。如果这样的地址不可用，中继代理可以从接收原始消息的接口将链路地址字段设置为链路本地地址。不建议这样做，因为可能需要在服务器配置中提供附加信息。详细讨论见[RFC7969]第3.2节。
This address will be used by the server to determine the link from which the client should be assigned leases and other configuration information.
服务器将使用此地址来确定从中为客户端分配租约和其他配置信息的链接。
The hop-count value in the Relay-forward message is set to 0.
中继转发消息中的跃点计数值设置为0。
If the relay agent cannot use the address in the link-address field to identify the interface through which the response to the client will be relayed, the relay agent MUST include an Interface-Id option (see Section 21.18) in the Relay-forward message. The server will include the Interface-Id option in its Relay-reply message. The relay agent sets the link-address field as described earlier in this subsection, regardless of whether the relay agent includes an Interface-Id option in the Relay-forward message.
如果中继代理无法使用链路地址字段中的地址来标识将通过哪个接口中继对客户端的响应，则中继代理必须在中继转发消息中包含接口Id选项（见第21.18节）。服务器将在其中继回复消息中包含接口Id选项。中继代理按照本小节前面所述设置链路地址字段，而不管中继代理是否在中继转发消息中包含接口Id选项。
If the message received by the relay agent is a Relay-forward message and the hop-count value in the message is greater than or equal to HOP_COUNT_LIMIT, the relay agent discards the received message.
如果中继代理接收到的消息是中继转发消息，且消息中的跃点计数值大于或等于跃点计数限制，则中继代理将丢弃接收到的消息。
The relay agent copies the source address from the IP datagram in which the message was received into the peer-address field in the Relay-forward message and sets the hop-count field to the value of the hop-count field in the received message incremented by 1.
中继代理将接收消息的IP数据报中的源地址复制到中继转发消息中的对等地址字段中，并将跃点计数字段设置为接收消息中的跃点计数字段的值加1。
If the source address from the IP datagram header of the received message is a globally scoped unicast address (i.e., GUA or ULA), the relay agent sets the link-address field to 0; otherwise, the relay agent sets the link-address field to a globally scoped unicast address (i.e., GUA or ULA) assigned to the interface on which the message was received or includes an Interface-Id option (see Section 21.18) to identify the interface on which the message was received.
如果来自所接收消息的IP数据报报头的源地址是全局范围的单播地址（即，GUA或ULA），则中继代理将链路地址字段设置为0；否则，中继代理将链路地址字段设置为分配给接收消息的接口的全局范围单播地址（即，GUA或ULA），或包括接口Id选项（见第21.18节），以标识接收消息的接口。
A relay agent forwards messages containing prefix delegation options in the same way as it would relay addresses (i.e., per Sections 19.1.1 and 19.1.2).
中继代理转发包含前缀委派选项的消息的方式与转发地址的方式相同（即，根据第19.1.1节和第19.1.2节）。
If a server communicates with a client through a relay agent about delegated prefixes, the server may need a protocol or other out-of-band communication to configure routing information for delegated prefixes on any router through which the client may forward traffic.
如果服务器通过中继代理与客户机就委派前缀进行通信，则服务器可能需要协议或其他带外通信来配置任何路由器上委派前缀的路由信息，客户机可通过该路由器转发流量。
The relay agent processes any options included in the Relay-reply message in addition to the Relay Message option (see Section 21.10).
中继代理处理中继回复消息中包括的任何选项，以及中继消息选项（参见第21.10节）。
The relay agent extracts the message from the Relay Message option and relays it to the address contained in the peer-address field of the Relay-reply message. Relay agents MUST NOT modify the message.
中继代理从中继消息选项提取消息，并将其中继到中继回复消息的对等地址字段中包含的地址。中继代理不得修改消息。
If the Relay-reply message includes an Interface-Id option (see Section 21.18), the relay agent relays the message from the server to the client on the link identified by the Interface-Id option. Otherwise, if the link-address field is not set to 0, the relay agent relays the message on the link identified by the link-address field.
如果中继回复消息包括接口Id选项（参见第21.18节），中继代理将消息从服务器中继到由接口Id选项标识的链路上的客户端。否则，如果链路地址字段未设置为0，中继代理将在链路地址字段标识的链路上中继消息。
If the relay agent receives a Relay-reply message, it MUST process the message as defined above, regardless of the type of message encapsulated in the Relay Message option.
如果中继代理收到中继回复消息，则无论中继消息选项中封装的消息类型如何，它都必须按照上述定义处理该消息。
A server uses a Relay-reply message to (1) return a response to a client if the original message from the client was relayed to the server in a Relay-forward message or (2) send a Reconfigure message to a client if the server does not have an address it can use to send the message directly to the client.
服务器使用中继回复消息（1）如果来自客户端的原始消息在中继转发消息中中继到服务器，则向客户端返回响应；或者（2）如果服务器没有可用于将消息直接发送到客户端的地址，则向客户端发送重新配置消息。
A response to the client MUST be relayed through the same relay agents as the original client message. The server causes this to happen by creating a Relay-reply message that includes a Relay Message option (see Section 21.10) containing the message for the next relay agent in the return path to the client. The contained Relay-reply message contains another Relay Message option to be sent to the next relay agent, and so on. The server must record the
对客户端的响应必须通过与原始客户端消息相同的中继代理进行中继。服务器通过创建包含中继消息选项（参见第21.10节）的中继回复消息来实现这一点，中继消息选项包含客户端返回路径中下一个中继代理的消息。包含的中继回复消息包含要发送到下一个中继代理的另一个中继消息选项，依此类推。服务器必须记录
contents of the peer-address fields in the received message so it can construct the appropriate Relay-reply message carrying the response from the server.
接收到的消息中的对等地址字段的内容，以便它可以构造适当的中继回复消息，从而承载来自服务器的响应。
For example, if client C sent a message that was relayed by relay agent A to relay agent B and then to the server, the server would send the following Relay-reply message to relay agent B:
例如，如果客户端C发送了一条由中继代理a中继到中继代理B然后再到服务器的消息，则服务器将向中继代理B发送以下中继回复消息：
msg-type: RELAY-REPL
hop-count: 1
link-address: 0
peer-address: A
Relay Message option containing the following:
msg-type: RELAY-REPL
hop-count: 0
link-address: address from link to which C is attached
peer-address: C
Relay Message option: <response from server>
msg-type: RELAY-REPL
hop-count: 1
link-address: 0
peer-address: A
Relay Message option containing the following:
msg-type: RELAY-REPL
hop-count: 0
link-address: address from link to which C is attached
peer-address: C
Relay Message option: <response from server>
Figure 10: Relay-reply Example
图10：中继应答示例
When sending a Reconfigure message to a client through a relay agent, the server creates a Relay-reply message that includes a Relay Message option containing the Reconfigure message for the next relay agent in the return path to the client. The server sets the peer-address field in the Relay-reply message header to the address of the client and sets the link-address field as required by the relay agent to relay the Reconfigure message to the client. The server obtains the addresses of the client and the relay agent through prior interaction with the client or through some external mechanism.
当通过中继代理向客户端发送重新配置消息时，服务器将创建一条中继回复消息，该消息包含一个中继消息选项，该选项包含客户端返回路径中下一个中继代理的重新配置消息。服务器将中继回复消息头中的对等地址字段设置为客户端的地址，并根据中继代理的要求设置链接地址字段，以将重新配置消息中继到客户端。服务器通过事先与客户机交互或通过某种外部机制获得客户机和中继代理的地址。
Each time a packet is relayed by a relay agent towards a server, a new encapsulation level is added around the packet. Each relay is allowed to insert additional options on the encapsulation level it added but MUST NOT change anything in the packet being encapsulated. If there are multiple relays between a client and a server, multiple encapsulations are used. Although it makes packet processing slightly more complex, it provides the major advantage of having a clear indication as to which relay inserted which option. The response packet is expected to travel through the same relays, but in reverse order. Each time a response packet is relayed back towards a client, one encapsulation level is removed.
每次中继代理向服务器中继数据包时，都会在数据包周围添加一个新的封装级别。允许每个中继在其添加的封装级别上插入附加选项，但不得更改正在封装的数据包中的任何内容。如果客户端和服务器之间有多个中继，则使用多个封装。尽管它使数据包处理稍微复杂一些，但它提供了一个主要优势，即可以清楚地指示插入了哪个中继和哪个选项。响应数据包预期通过相同的继电器，但顺序相反。每次将响应数据包中继回客户端时，都会删除一个封装级别。
In certain cases, relays can add one or more options. These options can be added for several reasons:
在某些情况下，继电器可以添加一个或多个选项。由于以下几个原因，可以添加这些选项：
- First, relays can provide additional information about the client. That source of information is usually more trusted by a server administrator, as it comes from the network infrastructure rather than the client and cannot be easily spoofed. These options can be used by the server to determine its allocation policy.
- 首先，中继可以提供有关客户端的附加信息。服务器管理员通常更信任该信息源，因为它来自网络基础设施而不是客户端，并且不容易被欺骗。服务器可以使用这些选项来确定其分配策略。
- Second, a relay may need some information to send a response back to the client. Relay agents are expected to be stateless (not retain any state after a packet has been processed). A relay agent may include the Interface-Id option (see Section 21.18), which will be echoed back in the response. It can include other options and ask the server to echo one or more of the options back in the response. These options can then be used by the relay agent to send the response back to the client, or for other needs. The client will never see these options. See [RFC4994] for details.
- 其次，中继可能需要一些信息才能将响应发送回客户端。中继代理应该是无状态的（在处理数据包后不保留任何状态）。中继代理可能包括接口Id选项（见第21.18节），该选项将在响应中回显。它可以包括其他选项，并要求服务器在响应中回显一个或多个选项。然后，中继代理可以使用这些选项将响应发送回客户端，或用于其他需要。客户永远不会看到这些选项。详见[RFC4994]。
- Third, sometimes a relay is the best device to provide values for certain options. A relay can insert an option into the packet being forwarded to the server and ask the server to pass that option back to the client. The client will receive that option. It should be noted that the server is the ultimate authority here, and -- depending on its configuration -- it may or may not send the option back to the client. See [RFC6422] for details.
- 第三，有时继电器是为某些选项提供值的最佳设备。中继可以在转发到服务器的数据包中插入一个选项，并要求服务器将该选项传递回客户端。客户将收到该选项。应该注意的是，服务器是这里的最终权威，并且——取决于它的配置——它可能会也可能不会将选项发送回客户端。详见[RFC6422]。
For various reasons, servers may need to retain the relay information after the packet processing is completed. One is a bulk leasequery mechanism that may ask for all addresses and/or prefixes that were assigned via a specific relay. A second is for the reconfigure mechanism. The server may choose to not send the Reconfigure message directly to the client but rather to send it via relays. This particular behavior is considered an implementation detail and is out of scope for this document.
出于各种原因，服务器可能需要在包处理完成后保留中继信息。一种是批量租赁机制，可请求通过特定中继分配的所有地址和/或前缀。第二个是重新配置机制。服务器可以选择不直接向客户端发送重新配置消息，而是通过中继发送。此特定行为被视为一个实现细节，不在本文档的范围内。
This document introduces two security mechanisms for the authentication of DHCP messages: (1) authentication (and encryption) of messages sent between servers and relay agents using IPsec and (2) protection against misconfiguration of a client caused by a Reconfigure message sent by a malicious DHCP server.
本文档介绍了用于验证DHCP消息的两种安全机制：（1）使用IPsec对服务器和中继代理之间发送的消息进行身份验证（和加密）和（2）防止恶意DHCP服务器发送的重新配置消息导致客户端配置错误。
The delayed authentication protocol, defined in [RFC3315], has been obsoleted by this document (see Section 25).
[RFC3315]中定义的延迟认证协议已被本文件废除（见第25节）。
Relay agents and servers that exchange messages can use IPsec as detailed in [RFC8213].
交换消息的中继代理和服务器可以使用IPsec，详见[RFC8213]。
Authentication of DHCP messages is accomplished through the use of the Authentication option (see Section 21.11). The authentication information carried in the Authentication option can be used to reliably identify the source of a DHCP message and to confirm that the contents of the DHCP message have not been tampered with.
DHCP消息的身份验证通过使用身份验证选项来完成（见第21.11节）。身份验证选项中携带的身份验证信息可用于可靠地识别DHCP消息的源，并确认DHCP消息的内容未被篡改。
The Authentication option provides a framework for multiple authentication protocols. One such protocol, RKAP, is defined in Section 20.4. Other protocols defined in the future will be specified in separate documents.
身份验证选项为多个身份验证协议提供了一个框架。第20.4节定义了一个此类协议RKAP。将来定义的其他协议将在单独的文件中指定。
Any DHCP message MUST NOT include more than one Authentication option.
任何DHCP消息不得包含多个身份验证选项。
The protocol field in the Authentication option identifies the specific protocol used to generate the authentication information carried in the option. The algorithm field identifies a specific algorithm within the authentication protocol; for example, the algorithm field specifies the hash algorithm used to generate the Message Authentication Code (MAC) in the Authentication option. The RDM field specifies the type of replay detection used in the replay detection field.
身份验证选项中的协议字段标识用于生成选项中包含的身份验证信息的特定协议。算法字段标识认证协议内的特定算法；例如，算法字段指定用于在身份验证选项中生成消息身份验证码（MAC）的哈希算法。RDM字段指定重播检测字段中使用的重播检测类型。
The RDM field of the Authentication option (see Section 21.11) determines the type of replay detection used in the replay detection field.
身份验证选项的RDM字段（参见第21.11节）确定了重播检测字段中使用的重播检测类型。
If the RDM field contains 0x00, the replay detection field MUST be set to the value of a strictly monotonically increasing 64-bit unsigned integer (modulo 2^64). Using this technique can reduce the danger of replay attacks. This method MUST be supported by all Authentication option protocols. One choice might be to use the 64-bit NTP timestamp format [RFC5905]).
如果RDM字段包含0x00，则重播检测字段必须设置为严格单调递增的64位无符号整数（模2^64）。使用此技术可以减少重播攻击的危险。所有身份验证选项协议都必须支持此方法。一种选择可能是使用64位NTP时间戳格式[RFC5905]）。
A client that receives a message with the RDM field set to 0x00 MUST compare its replay detection field with the previous value sent by that same server (based on the Server Identifier option; see Section 21.3) and only accept the message if the received value is greater and record this as the new value. If this is the first time
接收RDM字段设置为0x00的消息的客户端必须将其重播检测字段与同一服务器发送的上一个值进行比较（基于服务器标识符选项；请参见第21.3节），并且仅在接收到的值更大时才接受该消息，并将其记录为新值。如果这是第一次
a client processes an Authentication option sent by a server, the client MUST record the replay detection value and skip the replay detection check.
客户端处理服务器发送的身份验证选项，客户端必须记录重播检测值并跳过重播检测检查。
Servers that support the reconfigure mechanism MUST ensure that the replay detection value is retained between restarts. Failing to do so may cause clients to refuse Reconfigure messages sent by the server, effectively rendering the reconfigure mechanism useless.
支持重新配置机制的服务器必须确保在重新启动之间保留replay检测值。否则，可能会导致客户端拒绝服务器发送的重新配置消息，从而导致重新配置机制无效。
RKAP provides protection against misconfiguration of a client caused by a Reconfigure message sent by a malicious DHCP server. In this protocol, a DHCP server sends a reconfigure key to the client in the initial exchange of DHCP messages. The client records the reconfigure key for use in authenticating subsequent Reconfigure messages from that server. The server then includes a Hashed Message Authentication Code (HMAC) computed from the reconfigure key in subsequent Reconfigure messages.
RKAP提供保护，防止恶意DHCP服务器发送的重新配置消息导致客户端配置错误。在此协议中，DHCP服务器在DHCP消息的初始交换中向客户端发送重新配置密钥。客户端记录重新配置密钥，用于验证来自该服务器的后续重新配置消息。然后，服务器在随后的重新配置消息中包括根据重新配置密钥计算的哈希消息认证码（HMAC）。
Both the reconfigure key sent from the server to the client and the HMAC in subsequent Reconfigure messages are carried as the authentication information in an Authentication option (see Section 21.11). The format of the authentication information is defined in the following section.
从服务器发送到客户端的重新配置密钥和后续重新配置消息中的HMAC都作为身份验证选项中的身份验证信息携带（参见第21.11节）。认证信息的格式在下一节中定义。
RKAP is used (initiated by the server) only if the client and server have negotiated to use Reconfigure messages.
只有当客户端和服务器协商使用重新配置消息时，才会使用RKAP（由服务器启动）。
The following fields are set in an Authentication option (see Section 21.11) for RKAP:
在RKAP的身份验证选项（见第21.11节）中设置了以下字段：
protocol 3
议定书3
algorithm 1
算法1
RDM 0
RDM0
The format of the authentication information for RKAP is:
RKAP的身份验证信息格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Value (128 bits) |
+-+-+-+-+-+-+-+-+ |
. .
. .
. +-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Value (128 bits) |
+-+-+-+-+-+-+-+-+ |
. .
. .
. +-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11: RKAP Authentication Information
图11:RKAP身份验证信息
Type Type of data in the Value field carried in this option:
此选项中携带的值字段中的数据类型：
1 Reconfigure key value (used in the Reply message).
1重新配置键值（在回复消息中使用）。
2 HMAC-MD5 digest of the message (used in the Reconfigure message).
2条消息的HMAC-MD5摘要（用于重新配置消息）。
A 1-octet field.
一个1-octet字段。
Value Data as defined by the Type field. A 16-octet field.
由类型字段定义的值数据。16个八位组的字段。
The server selects a reconfigure key for a client during the Request/Reply, Solicit/Reply, or Information-request/Reply message exchange. The server records the reconfigure key and transmits that key to the client in an Authentication option (see Section 21.11) in the Reply message.
服务器在请求/答复、请求/答复或信息请求/答复消息交换期间为客户端选择重新配置密钥。服务器记录重新配置密钥，并在回复消息中通过身份验证选项（见第21.11节）将该密钥传输给客户端。
The reconfigure key is 128 bits long and MUST be a cryptographically strong random or pseudorandom number that cannot easily be predicted.
重新配置密钥的长度为128位，必须是无法轻易预测的加密强随机数或伪随机数。
To provide authentication for a Reconfigure message, the server selects a replay detection value according to the RDM selected by the server and computes an HMAC-MD5 of the Reconfigure message using the reconfigure key for the client. The server computes the HMAC-MD5 over the entire DHCP Reconfigure message, including the Authentication option; the HMAC-MD5 field in the Authentication option is set to 0 for the HMAC-MD5 computation. The server includes the HMAC-MD5 in the authentication information field in an Authentication option included in the Reconfigure message sent to the client.
为了为重新配置消息提供认证，服务器根据服务器选择的RDM选择重播检测值，并使用客户端的重新配置密钥计算重新配置消息的HMAC-MD5。服务器通过整个DHCP重新配置消息（包括身份验证选项）计算HMAC-MD5；对于HMAC-MD5计算，身份验证选项中的HMAC-MD5字段设置为0。服务器在发送给客户端的重新配置消息中包含的身份验证选项的身份验证信息字段中包含HMAC-MD5。
The client will receive a reconfigure key from the server in an Authentication option (see Section 21.11) in the initial Reply message from the server. The client records the reconfigure key for use in authenticating subsequent Reconfigure messages.
客户机将在来自服务器的初始回复消息中的身份验证选项（参见第21.11节）中从服务器接收重新配置密钥。客户端记录重新配置密钥以用于验证后续重新配置消息。
To authenticate a Reconfigure message, the client computes an HMAC-MD5 over the Reconfigure message, with zeroes substituted for the HMAC-MD5 field, using the reconfigure key received from the server. If this computed HMAC-MD5 matches the value in the Authentication option, the client accepts the Reconfigure message.
为了对重新配置消息进行身份验证，客户端使用从服务器接收的重新配置密钥，通过重新配置消息计算HMAC-MD5，用零替换HMAC-MD5字段。如果计算出的HMAC-MD5与身份验证选项中的值匹配，则客户端接受重新配置消息。
Options are used to carry additional information and parameters in DHCP messages. Every option shares a common base format, as described in Section 21.1. All values in options are represented in network byte order.
选项用于在DHCP消息中携带附加信息和参数。如第21.1节所述，每个期权共享一个共同的基本格式。选项中的所有值都以网络字节顺序表示。
This document describes the DHCP options defined as part of the base DHCP specification. Other options may be defined in the future in separate documents. See [RFC7227] for guidelines regarding the definition of new options. See Section 24 for additional information about the DHCPv6 "Option Codes" registry maintained by IANA.
本文档描述了作为基本DHCP规范一部分定义的DHCP选项。其他选项可能在将来的单独文件中定义。有关新选项定义的指南，请参见[RFC7227]。有关IANA维护的DHCPv6“选项代码”注册表的更多信息，请参见第24节。
Unless otherwise noted, each option may appear only in the options area of a DHCP message and may appear only once. If an option does appear multiple times, each instance is considered separate and the data areas of the options MUST NOT be concatenated or otherwise combined.
除非另有说明，否则每个选项只能出现在DHCP消息的选项区域中，并且只能出现一次。如果某个选项出现多次，则每个实例都被视为单独的，并且这些选项的数据区域不得连接或以其他方式组合。
Options that are allowed to appear only once are called "singleton options". The only non-singleton options defined in this document are the IA_NA (see Section 21.4), IA_TA (see Section 21.5), Vendor Class (see Section 21.16), Vendor-specific Information (see Section 21.17), and IA_PD (see Section 21.21) options. Also, IA Address (see Section 21.6) and IA Prefix (see Section 21.22) may appear in their respective IA options more than once.
只允许出现一次的选项称为“单例选项”。本文件中定义的唯一非单一选项是IA_NA（见第21.4节）、IA_TA（见第21.5节）、供应商类别（见第21.16节）、供应商特定信息（见第21.17节）和IA_PD（见第21.21节）选项。此外，IA地址（见第21.6节）和IA前缀（见第21.22节）可能会在各自的IA选项中出现多次。
The format of DHCP options is:
DHCP选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-data |
| (option-len octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-code | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| option-data |
| (option-len octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 12: Option Format
图12：选项格式
option-code An unsigned integer identifying the specific option type carried in this option. A 2-octet field.
选项代码标识此选项中包含的特定选项类型的无符号整数。两个八位组的字段。
option-len An unsigned integer giving the length of the option-data field in this option in octets. A 2-octet field.
option len一个无符号整数，给出此选项中选项数据字段的长度（以八位字节为单位）。两个八位组的字段。
option-data The data for the option; the format of this data depends on the definition of the option. A variable-length field (the length, in octets, is specified by option-len).
期权数据-期权的数据；此数据的格式取决于选项的定义。可变长度字段（长度以八位字节为单位，由选项len指定）。
DHCP options are scoped by using encapsulation. Some options apply generally to the client, some are specific to an IA, and some are specific to the addresses within an IA. These latter two cases are discussed in Sections 21.4, 21.5, and 21.6.
DHCP选项的范围通过使用封装来确定。有些选项通常适用于客户端，有些特定于IA，有些特定于IA中的地址。第21.4、21.5和21.6节讨论了后两种情况。
The Client Identifier option is used to carry a DUID (see Section 11) that identifies the client. The format of the Client Identifier option is:
客户端标识符选项用于携带识别客户端的DUID（见第11节）。客户端标识符选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_CLIENTID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. DUID .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_CLIENTID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. DUID .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 13: Client Identifier Option Format
图13：客户端标识符选项格式
option-code OPTION_CLIENTID (1).
选项代码选项\客户端ID（1）。
option-len Length of DUID in octets.
选项len DUID的长度（以八位字节为单位）。
DUID The DUID for the client.
DUID客户端的DUID。
The Server Identifier option is used to carry a DUID (see Section 11) that identifies the server. The format of the Server Identifier option is:
服务器标识符选项用于携带标识服务器的DUID（见第11节）。服务器标识符选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_SERVERID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. DUID .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_SERVERID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. DUID .
. (variable length) .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 14: Server Identifier Option Format
图14：服务器标识符选项格式
option-code OPTION_SERVERID (2).
选项代码选项\服务器ID（2）。
option-len Length of DUID in octets.
选项len DUID的长度（以八位字节为单位）。
DUID The DUID for the server.
DUID服务器的DUID。
The Identity Association for Non-temporary Addresses (IA_NA) option is used to carry an IA_NA, the parameters associated with the IA_NA, and the non-temporary addresses associated with the IA_NA.
非临时地址标识关联（IA_NA）选项用于携带IA_NA、与IA_NA关联的参数以及与IA_NA关联的非临时地址。
Addresses appearing in an IA_NA option are not temporary addresses (see Section 21.5).
IA_NA选项中出现的地址不是临时地址（见第21.5节）。
The format of the IA_NA option is:
IA_NA选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_NA | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. IA_NA-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_NA | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. IA_NA-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 15: Identity Association for Non-temporary Addresses Option Format
图15：非临时地址的标识关联选项格式
option-code OPTION_IA_NA (3).
选项代码选项IA_NA（3）。
option-len 12 + length of IA_NA-options field.
选项长度12+IA_NA选项字段的长度。
IAID The unique identifier for this IA_NA; the IAID must be unique among the identifiers for all of this client's IA_NAs. The number space for IA_NA IAIDs is separate from the number space for other IA option types (i.e., IA_TA and IA_PD). A 4-octet field containing an unsigned integer.
IAID此IA_NA的唯一标识符；IAID在该客户端的所有IA_NAs的标识符中必须是唯一的。IA_NA IAID的数字空间与其他IA选项类型（即IA_TA和IA_PD）的数字空间是分开的。包含无符号整数的4个八位字段。
T1 The time interval after which the client should contact the server from which the addresses in the IA_NA were obtained to extend the lifetimes of the addresses assigned to the IA_NA; T1 is a time duration relative to the current time expressed in units of seconds. A 4-octet field containing an unsigned integer.
T1时间间隔，在此时间间隔之后，客户端应与服务器联系，从服务器获取IA_NA中的地址，以延长分配给IA_NA的地址的生命周期；T1是相对于当前时间的持续时间，以秒为单位表示。包含无符号整数的4个八位字段。
T2 The time interval after which the client should contact any available server to extend the lifetimes of the addresses assigned to the IA_NA; T2 is a time duration relative to the current time expressed in units of seconds. A 4-octet field containing an unsigned integer.
T2客户端应联系任何可用服务器以延长分配给IA_NA的地址的生存期的时间间隔；T2是相对于当前时间的持续时间，以秒为单位表示。包含无符号整数的4个八位字段。
IA_NA-options Options associated with this IA_NA. A variable-length field (12 octets less than the value in the option-len field).
IA_NA—与此IA_NA关联的选项。可变长度字段（比选项len字段中的值小12个八位字节）。
The IA_NA-options field encapsulates those options that are specific to this IA_NA. For example, all of the IA Address options (see Section 21.6) carrying the addresses associated with this IA_NA are in the IA_NA-options field.
IA_NA-options字段封装了特定于此IA_NA的选项。例如，所有带有与此IA_NA相关地址的IA地址选项（见第21.6节）都位于IA_NA-options字段中。
Each IA_NA carries one "set" of non-temporary addresses; it is up to the server policy to determine how many addresses are assigned, but typically at most one address is assigned from each prefix assigned to the link to which the client is attached.
每个IA_NA带有一组非临时地址；由服务器策略确定分配了多少地址，但通常从分配给客户端连接到的链接的每个前缀中最多分配一个地址。
An IA_NA option may only appear in the options area of a DHCP message. A DHCP message may contain multiple IA_NA options (though each must have a unique IAID).
IA_NA选项只能出现在DHCP消息的选项区域中。DHCP消息可能包含多个IA_NA选项（尽管每个选项必须具有唯一的IAID）。
The status of any operations involving this IA_NA is indicated in a Status Code option (see Section 21.13) in the IA_NA-options field.
涉及此IA-NA的任何操作的状态在IA-NA-options字段中的状态代码选项（见第21.13节）中指示。
Note that an IA_NA has no explicit "lifetime" or "lease length" of its own. When the valid lifetimes of all of the addresses in an IA_NA have expired, the IA_NA can be considered as having expired. T1 and T2 are included to give servers explicit control over when a client recontacts the server about a specific IA_NA.
请注意，IA_NA本身没有明确的“寿命”或“租赁期限”。当IA_NA中所有地址的有效生存期已过期时，可以认为IA_NA已过期。T1和T2是为了让服务器明确控制客户端何时就特定IA_NA重新与服务器联系。
In a message sent by a client to a server, the T1 and T2 fields SHOULD be set to 0. The server MUST ignore any values in these fields in messages received from a client.
在客户端发送到服务器的消息中，T1和T2字段应设置为0。服务器必须忽略从客户端接收的消息中这些字段中的任何值。
In a message sent by a server to a client, the client MUST use the values in the T1 and T2 fields for the T1 and T2 times, unless values in those fields are 0. The values in the T1 and T2 fields are the number of seconds until T1 and T2 and are calculated since reception of the message.
在服务器发送给客户机的消息中，客户机必须在T1和T2时间内使用T1和T2字段中的值，除非这些字段中的值为0。T1和T2字段中的值是T1和T2之前的秒数，并且是自接收到消息后计算的。
As per Section 7.7, the value 0xffffffff is taken to mean "infinity" and should be used carefully.
根据第7.7节，值0xFFFFFF表示“无穷大”，应谨慎使用。
The server selects the T1 and T2 values to allow the client to extend the lifetimes of any addresses in the IA_NA before the lifetimes expire, even if the server is unavailable for some short period of time. Recommended values for T1 and T2 are 0.5 and 0.8 times the shortest preferred lifetime of the addresses in the IA that the server is willing to extend, respectively. If the "shortest" preferred lifetime is 0xffffffff ("infinity"), the recommended T1 and T2 values are also 0xffffffff. If the time at which the addresses in an IA_NA are to be renewed is to be left to the discretion of the client, the server sets the T1 and T2 values to 0. The client MUST follow the rules defined in Section 14.2.
服务器选择T1和T2值，以允许客户端在IA_NA中的任何地址的生存期到期之前延长其生存期，即使服务器在短时间内不可用。T1和T2的建议值分别是服务器愿意延长的IA中地址的最短首选生存期的0.5倍和0.8倍。如果“最短”首选寿命为0xFFFFFF（“无穷大”），则建议的T1和T2值也为0xFFFFFF。如果更新IA_NA中地址的时间由客户端决定，则服务器将T1和T2值设置为0。客户必须遵守第14.2节规定的规则。
If a client receives an IA_NA with T1 greater than T2 and both T1 and T2 are greater than 0, the client discards the IA_NA option and processes the remainder of the message as though the server had not included the invalid IA_NA option.
如果客户端接收到T1大于T2且T1和T2均大于0的IA_NA，则客户端将丢弃IA_NA选项并处理消息的其余部分，就像服务器未包含无效IA_NA选项一样。
The Identity Association for Temporary Addresses (IA_TA) option is used to carry an IA_TA, the parameters associated with the IA_TA, and the addresses associated with the IA_TA. All of the addresses in this option are used by the client as temporary addresses, as defined in [RFC4941]. The format of the IA_TA option is:
临时地址标识关联（IA_-TA）选项用于携带IA_-TA、与IA_-TA关联的参数以及与IA_-TA关联的地址。根据[RFC4941]中的定义，客户机将此选项中的所有地址用作临时地址。IA_TA选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_TA | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. IA_TA-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_TA | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. IA_TA-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 16: Identity Association for Temporary Addresses Option Format
图16：临时地址的标识关联选项格式
option-code OPTION_IA_TA (4).
选项代码选项IA_TA（4）。
option-len 4 + length of IA_TA-options field.
选项len 4+IA_TA-options字段的长度。
IAID The unique identifier for this IA_TA; the IAID must be unique among the identifiers for all of this client's IA_TAs. The number space for IA_TA IAIDs is separate from the number space for other IA option types (i.e., IA_NA and IA_PD). A 4-octet field containing an unsigned integer.
IAID此IA_TA的唯一标识符；IAID在该客户端的所有IA_TA的标识符中必须是唯一的。IA_TA IAID的数字空间与其他IA选项类型（即IA_NA和IA_PD）的数字空间是分开的。包含无符号整数的4个八位字段。
IA_TA-options Options associated with this IA_TA. A variable-length field (4 octets less than the value in the option-len field).
IA_TA—与此IA_TA关联的选项。可变长度字段（比选项len字段中的值小4个八位字节）。
The IA_TA-options field encapsulates those options that are specific to this IA_TA. For example, all of the IA Address options (see Section 21.6) carrying the addresses associated with this IA_TA are in the IA_TA-options field.
IA_TA-options字段封装了特定于此IA_TA的选项。例如，携带与此IA_TA相关地址的所有IA地址选项（见第21.6节）都位于IA_TA-options字段中。
Each IA_TA carries one "set" of temporary addresses. It is up to the server policy to determine how many addresses are assigned.
每个IA_TA都有一套临时地址。由服务器策略决定分配多少地址。
An IA_TA option may only appear in the options area of a DHCP message. A DHCP message may contain multiple IA_TA options (though each must have a unique IAID).
IA_TA选项只能出现在DHCP消息的选项区域中。DHCP消息可能包含多个IA_TA选项（尽管每个选项必须具有唯一的IAID）。
The status of any operations involving this IA_TA is indicated in a Status Code option (see Section 21.13) in the IA_TA-options field.
涉及此IA_TA的任何操作的状态在IA_TA-options字段中的状态代码选项（见第21.13节）中指示。
Note that an IA has no explicit "lifetime" or "lease length" of its own. When the valid lifetimes of all of the addresses in an IA_TA have expired, the IA can be considered as having expired.
请注意，IA本身没有明确的“寿命”或“租赁期限”。当IA_TA中所有地址的有效生存期已过期时，IA可视为已过期。
An IA_TA option does not include values for T1 and T2. A client MAY request that the valid lifetime on temporary addresses be extended by including the addresses in an IA_TA option sent in a Renew or Rebind message to a server. For example, a client would request an extension on the valid lifetime of a temporary address to allow an application to continue to use an established TCP connection. Extending only the valid, but not the preferred, lifetime means the address will end up in a deprecated state eventually. Existing connections could continue, but no new ones would be created using that address.
IA_TA选项不包括T1和T2的值。客户端可以通过将地址包含在续订或重新绑定消息中发送到服务器的IA_TA选项中，请求延长临时地址的有效生存期。例如，客户机将请求延长临时地址的有效生存期，以允许应用程序继续使用已建立的TCP连接。仅扩展有效（而非首选）生存期意味着地址最终将处于不推荐状态。现有连接可以继续，但不会使用该地址创建新的连接。
The client obtains new temporary addresses by sending an IA_TA option with a new IAID to a server. Requesting new temporary addresses from the server is the equivalent of generating new temporary addresses as described in [RFC4941]. The server will generate new temporary addresses and return them to the client. The client should request new temporary addresses before the lifetimes on the previously assigned addresses expire.
客户端通过向服务器发送带有新IAID的IA_TA选项来获得新的临时地址。从服务器请求新的临时地址相当于生成[RFC4941]中所述的新临时地址。服务器将生成新的临时地址并将其返回给客户端。客户端应在先前分配的地址的生存期到期之前请求新的临时地址。
A server MUST return the same set of temporary addresses for the same IA_TA (as identified by the IAID) as long as those addresses are still valid. After the lifetimes of the addresses in an IA_TA have expired, the IAID may be reused to identify a new IA_TA with new temporary addresses.
服务器必须为相同的IA_TA（由IAID标识）返回相同的临时地址集，只要这些地址仍然有效。在IA_-TA中的地址的生存期到期后，可以重用IAID以用新的临时地址标识新的IA_-TA。
The IA Address option is used to specify an address associated with an IA_NA or an IA_TA. The IA Address option must be encapsulated in the IA_NA-options field of an IA_NA option (see Section 21.4) or the IA_TA-options field of an IA_TA option (see Section 21.5). The IAaddr-options field encapsulates those options that are specific to this address.
IA地址选项用于指定与IA NA或IA TA关联的地址。IA地址选项必须封装在IA_NA选项的IA_NA-options字段（见第21.4节）或IA_TA选项的IA_TA-options字段（见第21.5节）中。IAaddr options字段封装了特定于此地址的选项。
The format of the IA Address option is:
IA地址选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IAADDR | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6-address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| preferred-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| valid-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. IAaddr-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IAADDR | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| IPv6-address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| preferred-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| valid-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. IAaddr-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 17: IA Address Option Format
图17:IA地址选项格式
option-code OPTION_IAADDR (5).
选项代码选项_IAADDR（5）。
option-len 24 + length of IAaddr-options field.
选项长度24+IAaddr选项字段的长度。
IPv6-address An IPv6 address. A client MUST NOT form an implicit prefix with a length other than 128 for this address. A 16-octet field.
IPv6地址IPv6地址。对于此地址，客户端不得形成长度不是128的隐式前缀。16个八位组的字段。
preferred-lifetime The preferred lifetime for the address in the option, expressed in units of seconds. A 4-octet field containing an unsigned integer.
首选生存期选项中地址的首选生存期，以秒为单位。包含无符号整数的4个八位字段。
valid-lifetime The valid lifetime for the address in the option, expressed in units of seconds. A 4-octet field containing an unsigned integer.
有效生存期选项中地址的有效生存期，以秒为单位。包含无符号整数的4个八位字段。
IAaddr-options Options associated with this address. A variable-length field (24 octets less than the value in the option-len field).
与此地址关联的IAaddr选项。可变长度字段（比选项len字段中的值小24个八位字节）。
In a message sent by a client to a server, the preferred-lifetime and valid-lifetime fields SHOULD be set to 0. The server MUST ignore any received values.
在客户端发送到服务器的消息中，首选生存期和有效生存期字段应设置为0。服务器必须忽略任何接收到的值。
The client SHOULD NOT send the IA Address option with an unspecified address (::).
客户端不应发送带有未指定地址（：）的IA地址选项。
In a message sent by a server to a client, the client MUST use the values in the preferred-lifetime and valid-lifetime fields for the preferred and valid lifetimes. The values in these fields are the number of seconds remaining in each lifetime.
在服务器发送给客户端的消息中，客户端必须使用首选生存期和有效生存期字段中的值作为首选和有效生存期。这些字段中的值是每个生命周期中剩余的秒数。
The client MUST discard any addresses for which the preferred lifetime is greater than the valid lifetime.
客户端必须丢弃首选生存期大于有效生存期的任何地址。
As per Section 7.7, if the valid lifetime of an address is 0xffffffff, it is taken to mean "infinity" and should be used carefully.
根据第7.7节，如果地址的有效生存期为0xFFFFFF，则表示“无限”，应谨慎使用。
More than one IA Address option can appear in an IA_NA option or an IA_TA option.
IA_NA选项或IA_TA选项中可以出现多个IA Address选项。
The status of any operations involving this IA Address is indicated in a Status Code option in the IAaddr-options field, as specified in Section 21.13.
根据第21.13节的规定，涉及此IA地址的任何操作的状态在IAaddr options字段的状态代码选项中显示。
The Option Request option is used to identify a list of options in a message between a client and a server. The format of the Option Request option is:
Option Request选项用于标识客户端和服务器之间消息中的选项列表。选项请求选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ORO | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| requested-option-code-1 | requested-option-code-2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ORO | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| requested-option-code-1 | requested-option-code-2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 18: Option Request Option Format
图18：选项请求选项格式
option-code OPTION_ORO (6).
选项代码选项_ORO（6）。
option-len 2 * number of requested options.
选项len 2*请求的选项数。
requested-option-code-n The option code for an option requested by the client. Each option code is a 2-octet field containing an unsigned integer.
requested-option-code-n客户端请求的选项的选项代码。每个选项代码都是一个包含无符号整数的2八位字段。
A client MUST include an Option Request option in a Solicit, Request, Renew, Rebind, or Information-request message to inform the server about options the client wants the server to send to the client. For certain message types, some option codes MUST be included in the Option Request option; see Table 4 for details.
客户机必须在请求、请求、续订、重新绑定或信息请求消息中包含选项请求选项，以通知服务器客户机希望服务器发送给客户机的选项。对于某些消息类型，某些选项代码必须包含在选项请求选项中；详见表4。
The Option Request option MUST NOT include the following options:
选项请求选项不得包括以下选项：
- Client Identifier (see Section 21.2)
- 客户标识符（见第21.2节）
- Server Identifier (see Section 21.3)
- 服务器标识符（见第21.3节）
- IA_NA (see Section 21.4)
- IA_NA（见第21.4节）
- IA_TA (see Section 21.5)
- IA_TA（见第21.5节）
- IA_PD (see Section 21.21)
- IA_PD（见第21.21节）
- IA Address (see Section 21.6)
- IA地址（见第21.6节）
- IA Prefix (see Section 21.22)
- IA前缀（见第21.22节）
- Option Request (this section)
- 选项请求（本节）
- Elapsed Time (see Section 21.9)
- 运行时间（见第21.9节）
- Preference (see Section 21.8)
- 首选项（见第21.8节）
- Relay Message (see Section 21.10)
- 中继信息（见第21.10节）
- Authentication (see Section 21.11)
- 认证（见第21.11节）
- Server Unicast (see Section 21.12)
- 服务器单播（见第21.12节）
- Status Code (see Section 21.13)
- 状态代码（见第21.13节）
- Rapid Commit (see Section 21.14)
- 快速提交（见第21.14节）
- User Class (see Section 21.15)
- 用户类别（见第21.15节）
- Vendor Class (see Section 21.16)
- 供应商类别（见第21.16节）
- Interface-Id (see Section 21.18)
- 接口Id（见第21.18节）
- Reconfigure Message (see Section 21.19)
- 重新配置信息（见第21.19节）
- Reconfigure Accept (see Section 21.20)
- 重新配置接受（见第21.20节）
Other top-level options MUST appear in the Option Request option or they will not be sent by the server. Only top-level options MAY appear in the Option Request option. Options encapsulated in a container option SHOULD NOT appear in an Option Request option; see [RFC7598] for an example of container options. However, options MAY be defined that specify exceptions to this restriction on including encapsulated options in an Option Request option. For example, the Option Request option MAY be used to signal support for a feature even when that option is encapsulated, as in the case of the Prefix Exclude option [RFC6603]. See Table 4.
其他顶级选项必须出现在选项请求选项中，否则服务器将不会发送这些选项。选项请求选项中只能显示顶级选项。封装在容器选项中的选项不应出现在选项请求选项中；有关容器选项的示例，请参见[RFC7598]。但是，可以定义一些选项，指定在选项请求选项中包含封装选项的例外情况。例如，选项请求选项可用于表示对某个特性的支持，即使该选项已封装，如前缀排除选项[RFC6603]的情况。见表4。
The Preference option is sent by a server to a client to control the selection of a server by the client.
首选项选项由服务器发送到客户端，以控制客户端对服务器的选择。
The format of the Preference option is:
首选项选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_PREFERENCE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| pref-value |
+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_PREFERENCE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| pref-value |
+-+-+-+-+-+-+-+-+
Figure 19: Preference Option Format
图19：首选项选项格式
option-code OPTION_PREFERENCE (7).
选项代码选项_首选项（7）。
option-len 1.
选项1。
pref-value The preference value for the server in this message. A 1-octet unsigned integer.
pref value此消息中服务器的首选项值。一个1-octet无符号整数。
A server MAY include a Preference option in an Advertise message to control the selection of a server by the client. See Section 18.2.9 for information regarding the use of the Preference option by the client and the interpretation of the Preference option data value.
服务器可以在播发消息中包括首选项选项，以控制客户端对服务器的选择。有关客户使用优先选择权和解释优先选择权数据值的信息，请参见第18.2.9节。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ELAPSED_TIME | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| elapsed-time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_ELAPSED_TIME | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| elapsed-time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 20: Elapsed Time Option Format
图20：运行时间选项格式
option-code OPTION_ELAPSED_TIME (8).
选项代码选项已用时间（8）。
option-len 2.
选项2。
elapsed-time The amount of time since the client began its current DHCP transaction. This time is expressed in hundredths of a second (10^-2 seconds). A 2-octet field containing an unsigned integer.
已用时间自客户端开始其当前DHCP事务以来的时间量。此时间以百分之一秒（10^-2秒）表示。包含无符号整数的2个八位字节字段。
A client MUST include an Elapsed Time option in messages to indicate how long the client has been trying to complete a DHCP message exchange. The elapsed time is measured from the time at which the client sent the first message in the message exchange, and the elapsed-time field is set to 0 in the first message in the message exchange. Servers and relay agents use the data value in this option as input to policy that controls how a server responds to a client message. For example, the Elapsed Time option allows a secondary DHCP server to respond to a request when a primary server has not answered in a reasonable time. The elapsed-time value is a 16-bit (2-octet) unsigned integer. The client uses the value 0xffff to represent any elapsed-time values greater than the largest time value that can be represented in the Elapsed Time option.
客户端必须在消息中包含已用时间选项，以指示客户端尝试完成DHCP消息交换的时间。已用时间从客户端在消息交换中发送第一条消息的时间开始测量，并且已用时间字段在消息交换中的第一条消息中设置为0。服务器和中继代理使用此选项中的数据值作为策略的输入，该策略控制服务器如何响应客户端消息。例如，当主服务器在合理的时间内没有响应请求时，“已用时间”选项允许辅助DHCP服务器响应请求。已用时间值是一个16位（2八位）无符号整数。客户机使用值0xffff表示任何大于可在“已用时间”选项中表示的最大时间值的已用时间值。
The Relay Message option carries a DHCP message in a Relay-forward or Relay-reply message.
中继消息选项在中继转发或中继回复消息中携带DHCP消息。
The format of the Relay Message option is:
中继消息选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RELAY_MSG | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. DHCP-relay-message .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RELAY_MSG | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. DHCP-relay-message .
. .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 21: Relay Message Option Format
图21：中继消息选项格式
option-code OPTION_RELAY_MSG (9).
选项代码选项继电器消息（9）。
option-len Length of DHCP-relay-message field.
选项len DHCP中继消息字段的长度。
DHCP-relay-message In a Relay-forward message, the received message, relayed verbatim to the next relay agent or server; in a Relay-reply message, the message to be copied and relayed to the relay agent or client whose address is in the peer-address field of the Relay-reply message. The length, in octets, is specified by option-len.
DHCP中继消息在中继转发消息中，接收到的消息逐字中继到下一个中继代理或服务器；在中继回复消息中，要复制并中继到中继代理或客户端的消息，其地址位于中继回复消息的对等地址字段中。长度（以八位字节为单位）由选项len指定。
The Authentication option carries authentication information to authenticate the identity and contents of DHCP messages. The use of the Authentication option is described in Section 20. The delayed authentication protocol, defined in [RFC3315], has been obsoleted by this document, due to lack of usage (see Section 25). The format of the Authentication option is:
身份验证选项携带身份验证信息，以验证DHCP消息的身份和内容。第20节描述了认证选项的使用。[RFC3315]中定义的延迟认证协议已被本文件废除，原因是缺乏使用（见第25节）。身份验证选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_AUTH | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| protocol | algorithm | RDM | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| replay detection (64 bits) +-+-+-+-+-+-+-+-+
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. authentication information .
. (variable length) .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_AUTH | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| protocol | algorithm | RDM | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| replay detection (64 bits) +-+-+-+-+-+-+-+-+
| | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. authentication information .
. (variable length) .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 22: Authentication Option Format
图22：身份验证选项格式
option-code OPTION_AUTH (11).
选项代码选项_AUTH（11）。
option-len 11 + length of authentication information field.
选项len 11+身份验证信息字段的长度。
protocol The authentication protocol used in this Authentication option. A 1-octet unsigned integer.
协议此身份验证选项中使用的身份验证协议。一个1-octet无符号整数。
algorithm The algorithm used in the authentication protocol. A 1-octet unsigned integer.
算法身份验证协议中使用的算法。一个1-octet无符号整数。
RDM The replay detection method used in this Authentication option. A 1-octet unsigned integer.
RDM此身份验证选项中使用的重播检测方法。一个1-octet无符号整数。
replay detection The replay detection information for the RDM. A 64-bit (8-octet) field.
重播检测RDM的重播检测信息。一个64位（8八位字节）字段。
authentication information The authentication information, as specified by the protocol and algorithm used in this Authentication option. A variable-length field (11 octets less than the value in the option-len field).
身份验证信息此身份验证选项中使用的协议和算法指定的身份验证信息。可变长度字段（比选项len字段中的值小11个八位字节）。
IANA maintains a registry for the protocol, algorithm, and RDM values at <https://www.iana.org/assignments/auth-namespaces>.
IANA在以下位置维护协议、算法和RDM值的注册表：<https://www.iana.org/assignments/auth-namespaces>.
The server sends this option to a client to indicate to the client that it is allowed to unicast messages to the server. The format of the Server Unicast option is:
服务器将此选项发送到客户端，以向客户端指示允许将消息单播到服务器。服务器单播选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_UNICAST | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| server-address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_UNICAST | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| server-address |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 23: Server Unicast Option Format
图23：服务器单播选项格式
option-code OPTION_UNICAST (12).
选项代码选项_单播（12）。
option-len 16.
选项16。
server-address The 128-bit address to which the client should send messages delivered using unicast.
服务器地址客户端应将使用单播发送的消息发送到的128位地址。
The server specifies in the server-address field the address to which the client is to send unicast messages. When a client receives this option, where permissible and appropriate the client sends messages directly to the server using the address specified in the server-address field of the option.
服务器在服务器地址字段中指定客户端要向其发送单播消息的地址。当客户端收到此选项时，在允许和适当的情况下，客户端使用该选项的“服务器地址”字段中指定的地址直接向服务器发送消息。
When the server sends a Server Unicast option to the client, some messages from the client will not be relayed by relay agents and will not include relay agent options from the relay agents. Therefore, a server should only send a Server Unicast option to a client when relay agents are not sending relay agent options. A DHCP server rejects any messages sent inappropriately using unicast to ensure that messages are relayed by relay agents when relay agent options are in use.
当服务器向客户端发送服务器单播选项时，来自客户端的某些消息将不会由中继代理转发，并且不会包括来自中继代理的中继代理选项。因此，当中继代理不发送中继代理选项时，服务器只应向客户端发送服务器单播选项。DHCP服务器拒绝使用单播不当发送的任何消息，以确保在使用中继代理选项时由中继代理中继消息。
Details about when the client may send messages to the server using unicast are provided in Section 18.
有关客户端何时可以使用单播向服务器发送消息的详细信息，请参见第18节。
This option returns a status indication related to the DHCP message or option in which it appears. The format of the Status Code option is:
此选项返回与DHCP消息或其出现的选项相关的状态指示。状态代码选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_STATUS_CODE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| status-code | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. .
. status-message .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_STATUS_CODE | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| status-code | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
. .
. status-message .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 24: Status Code Option Format
图24：状态代码选项格式
option-code OPTION_STATUS_CODE (13).
选项代码选项状态代码（13）。
option-len 2 + length of status-message field.
选项len 2+状态消息字段的长度。
status-code The numeric code for the status encoded in this option. A 2-octet field containing an unsigned integer.
状态代码此选项中编码的状态的数字代码。包含无符号整数的2个八位字节字段。
status-message A UTF-8 encoded [RFC3629] text string suitable for display to an end user. MUST NOT be null-terminated. A variable-length field (2 octets less than the value in the option-len field).
状态消息适用于向最终用户显示的UTF-8编码[RFC3629]文本字符串。不能以null结尾。可变长度字段（比选项len字段中的值小2个八位字节）。
A Status Code option may appear in the "options" field of a DHCP message and/or in the "options" field of another option. If the Status Code option does not appear in a message in which the option could appear, the status of the message is assumed to be Success.
状态代码选项可能出现在DHCP消息的“选项”字段和/或另一选项的“选项”字段中。如果状态代码选项未出现在可能出现该选项的消息中，则假定该消息的状态为成功。
The status-code values previously defined by [RFC3315] and [RFC3633] are:
[RFC3315]和[RFC3633]先前定义的状态代码值为：
+---------------+------+--------------------------------------------+
| Name | Code | Description |
+---------------+------+--------------------------------------------+
| Success | 0 | Success. |
| | | |
| UnspecFail | 1 | Failure, reason unspecified; this status |
| | | code is sent by either a client or a |
| | | server to indicate a failure not |
| | | explicitly specified in this document. |
| | | |
| NoAddrsAvail | 2 | The server has no addresses available to |
| | | assign to the IA(s). |
| | | |
| NoBinding | 3 | Client record (binding) unavailable. |
| | | |
| NotOnLink | 4 | The prefix for the address is not |
| | | appropriate for the link to which the |
| | | client is attached. |
| | | |
| UseMulticast | 5 | Sent by a server to a client to force the |
| | | client to send messages to the server |
| | | using the |
| | | All_DHCP_Relay_Agents_and_Servers |
| | | multicast address. |
| | | |
| NoPrefixAvail | 6 | The server has no prefixes available to |
| | | assign to the IA_PD(s). |
+---------------+------+--------------------------------------------+
+---------------+------+--------------------------------------------+
| Name | Code | Description |
+---------------+------+--------------------------------------------+
| Success | 0 | Success. |
| | | |
| UnspecFail | 1 | Failure, reason unspecified; this status |
| | | code is sent by either a client or a |
| | | server to indicate a failure not |
| | | explicitly specified in this document. |
| | | |
| NoAddrsAvail | 2 | The server has no addresses available to |
| | | assign to the IA(s). |
| | | |
| NoBinding | 3 | Client record (binding) unavailable. |
| | | |
| NotOnLink | 4 | The prefix for the address is not |
| | | appropriate for the link to which the |
| | | client is attached. |
| | | |
| UseMulticast | 5 | Sent by a server to a client to force the |
| | | client to send messages to the server |
| | | using the |
| | | All_DHCP_Relay_Agents_and_Servers |
| | | multicast address. |
| | | |
| NoPrefixAvail | 6 | The server has no prefixes available to |
| | | assign to the IA_PD(s). |
+---------------+------+--------------------------------------------+
Table 3: Status Code Definitions
表3：状态代码定义
See the "Status Codes" registry at <https://www.iana.org/assignments/ dhcpv6-parameters> for the current list of status codes.
请参阅“状态代码”注册表，网址为<https://www.iana.org/assignments/ dhcpv6参数>用于当前状态代码列表。
The Rapid Commit option is used to signal the use of the two-message exchange for address assignment. The format of the Rapid Commit option is:
快速提交选项用于发出使用两条消息交换进行地址分配的信号。快速提交选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RAPID_COMMIT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RAPID_COMMIT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 25: Rapid Commit Option Format
图25：快速提交选项格式
option-code OPTION_RAPID_COMMIT (14).
选项代码选项快速提交（14）。
option-len 0.
选项len 0。
A client MAY include this option in a Solicit message if the client is prepared to perform the Solicit/Reply message exchange described in Section 18.2.1.
如果客户准备执行第18.2.1节所述的请求/回复消息交换，则客户可以在请求消息中包含此选项。
A server MUST include this option in a Reply message sent in response to a Solicit message when completing the Solicit/Reply message exchange.
在完成请求/回复消息交换时，服务器必须在响应请求消息而发送的回复消息中包含此选项。
DISCUSSION:
讨论：
Each server that responds with a Reply to a Solicit that includes a Rapid Commit option will commit the leases in the Reply message to the client but will not receive any confirmation that the client has received the Reply message. Therefore, if more than one server responds to a Solicit that includes a Rapid Commit option, all but one server will commit leases that are not actually used by the client; this could result in incorrect address information in DNS if the DHCP servers update DNS [RFC4704], and responses to leasequery requests [RFC5007] may include information on leases not in use by the client.
对于包含快速提交选项的请求，每个服务器都会在回复消息中将租约提交给客户端，但不会收到客户端已收到回复消息的任何确认。因此，如果多个服务器响应包含快速提交选项的请求，则除一个服务器外，所有服务器都将提交客户端实际未使用的租约；如果DHCP服务器更新DNS[RFC4704]，这可能会导致DNS中的地址信息不正确，并且对租赁请求[RFC5007]的响应可能包括有关客户端未使用的租赁的信息。
The problem of unused leases can be minimized by designing the DHCP service so that only one server responds to the Solicit or by using relatively short lifetimes for newly assigned leases.
通过设计DHCP服务，使只有一台服务器响应请求，或者为新分配的租约使用相对较短的生存期，可以将未使用租约的问题降至最低。
The User Class option is used by a client to identify the type or category of users or applications it represents.
用户类选项由客户端用来标识它所代表的用户或应用程序的类型或类别。
The format of the User Class option is:
用户类选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_USER_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. user-class-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_USER_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. user-class-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 26: User Class Option Format
图26：用户类选项格式
option-code OPTION_USER_CLASS (15).
选项代码选项用户类（15）。
option-len Length of user-class-data field.
选项len用户类数据字段的长度。
user-class-data The user classes carried by the client. The length, in octets, is specified by option-len.
用户类数据客户端携带的用户类。长度（以八位字节为单位）由选项len指定。
The information contained in the data area of this option is contained in one or more opaque fields that represent the user class or classes of which the client is a member. A server selects configuration information for the client based on the classes identified in this option. For example, the User Class option can be used to configure all clients of people in the accounting department with a different printer than clients of people in the marketing department. The user class information carried in this option MUST be configurable on the client.
此选项的数据区域中包含的信息包含在一个或多个不透明字段中，这些字段表示客户端所属的一个或多个用户类。服务器根据此选项中标识的类选择客户端的配置信息。例如，用户类选项可用于将会计部门人员的所有客户机配置为与营销部门人员的客户机不同的打印机。此选项中包含的用户类信息必须在客户端上可配置。
The data area of the User Class option MUST contain one or more instances of user-class-data information. Each instance of user-class-data is formatted as follows:
用户类选项的数据区域必须包含一个或多个用户类数据信息实例。用户类数据的每个实例的格式如下：
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| user-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| user-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
Figure 27: Format of user-class-data Field
图27：用户类数据字段的格式
The user-class-len field is 2 octets long and specifies the length of the opaque user-class-data in network byte order.
用户类len字段的长度为2个八位字节，并以网络字节顺序指定不透明用户类数据的长度。
A server interprets the classes identified in this option according to its configuration to select the appropriate configuration information for the client. A server may use only those user classes that it is configured to interpret in selecting configuration information for a client and ignore any other user classes. In response to a message containing a User Class option, a server may include a User Class option containing those classes that were successfully interpreted by the server so that the client can be informed of the classes interpreted by the server.
服务器根据其配置解释此选项中标识的类，以便为客户端选择适当的配置信息。在为客户机选择配置信息时，服务器只能使用其配置为解释的那些用户类，而忽略任何其他用户类。作为对包含用户类选项的消息的响应，服务器可以包括包含由服务器成功解释的那些类的用户类选项，以便可以将由服务器解释的类通知客户端。
This option is used by a client to identify the vendor that manufactured the hardware on which the client is running. The information contained in the data area of this option is contained in one or more opaque fields that identify details of the hardware configuration. The format of the Vendor Class option is:
客户端使用此选项来标识制造客户端运行的硬件的供应商。此选项的数据区域中包含的信息包含在一个或多个不透明字段中，这些字段标识硬件配置的详细信息。供应商类选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-class-data .
. . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-class-data .
. . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 28: Vendor Class Option Format
图28：供应商类选项格式
option-code OPTION_VENDOR_CLASS (16).
选项代码选项\供应商\类别（16）。
option-len 4 + length of vendor-class-data field.
选项len 4+供应商类别数据字段的长度。
enterprise-number The vendor's registered Enterprise Number as maintained by IANA [IANA-PEN]. A 4-octet field containing an unsigned integer.
企业编号由IANA维护的供应商注册企业编号[IANA-PEN]。包含无符号整数的4个八位字段。
vendor-class-data The hardware configuration of the node on which the client is running. A variable-length field (4 octets less than the value in the option-len field).
供应商类数据运行客户端的节点的硬件配置。可变长度字段（比选项len字段中的值小4个八位字节）。
The vendor-class-data field is composed of a series of separate items, each of which describes some characteristic of the client's hardware configuration. Examples of vendor-class-data instances might include the version of the operating system the client is running or the amount of memory installed on the client.
供应商类数据字段由一系列单独的项组成，每个项描述客户机硬件配置的某些特征。供应商类数据实例的示例可能包括客户端正在运行的操作系统版本或客户端上安装的内存量。
Each instance of vendor-class-data is formatted as follows:
供应商类数据的每个实例的格式如下：
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| vendor-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| vendor-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
Figure 29: Format of vendor-class-data Field
图29：供应商类别数据字段的格式
The vendor-class-len field is 2 octets long and specifies the length of the opaque vendor-class-data in network byte order.
供应商类len字段的长度为2个八位字节，并以网络字节顺序指定不透明供应商类数据的长度。
Servers and clients MUST NOT include more than one instance of OPTION_VENDOR_CLASS with the same Enterprise Number. Each instance of OPTION_VENDOR_CLASS can carry multiple vendor-class-data instances.
服务器和客户端不得包含多个具有相同企业编号的OPTION_VENDOR_类实例。OPTION_VENDOR_类的每个实例都可以携带多个VENDOR类数据实例。
This option is used by clients and servers to exchange vendor-specific information.
客户端和服务器使用此选项交换特定于供应商的信息。
The format of the Vendor-specific Information option is:
供应商特定信息选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_OPTS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_OPTS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 30: Vendor-specific Information Option Format
图30：供应商特定信息选项格式
option-code OPTION_VENDOR_OPTS (17).
选项代码选项供应商选项（17）。
option-len 4 + length of vendor-option-data field.
选项len 4+供应商选项数据字段的长度。
enterprise-number The vendor's registered Enterprise Number as maintained by IANA [IANA-PEN]. A 4-octet field containing an unsigned integer.
企业编号由IANA维护的供应商注册企业编号[IANA-PEN]。包含无符号整数的4个八位字段。
vendor-option-data Vendor options, interpreted by vendor-specific code on the clients and servers. A variable-length field (4 octets less than the value in the option-len field).
供应商选项数据供应商选项，由客户机和服务器上特定于供应商的代码解释。可变长度字段（比选项len字段中的值小4个八位字节）。
The definition of the information carried in this option is vendor specific. The vendor is indicated in the enterprise-number field. Use of vendor-specific information allows enhanced operation, utilizing additional features in a vendor's DHCP implementation. A DHCP client that does not receive requested vendor-specific information will still configure the node's IPv6 stack to be functional.
此选项中包含的信息的定义是特定于供应商的。供应商在“企业编号”字段中指明。使用特定于供应商的信息可以增强操作，利用供应商DHCP实现中的附加功能。未接收请求的供应商特定信息的DHCP客户端仍将配置节点的IPv6堆栈以使其正常工作。
The vendor-option-data field MUST be encoded as a sequence of code/length/value fields of format identical to the DHCP options (see Section 21.1). The sub-option codes are defined by the vendor identified in the enterprise-number field and are not managed by IANA. Each of the sub-options is formatted as follows:
供应商选项数据字段必须编码为与DHCP选项格式相同的代码/长度/值字段序列（见第21.1节）。子选项代码由企业编号字段中标识的供应商定义，不由IANA管理。每个子选项的格式如下所示：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-opt-code | sub-option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. sub-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-opt-code | sub-option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. sub-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 31: Vendor-specific Options Format
图31：特定于供应商的选项格式
sub-opt-code The code for the sub-option. A 2-octet field.
子选项代码子选项的代码。两个八位组的字段。
sub-option-len An unsigned integer giving the length of the sub-option-data field in this sub-option in octets. A 2-octet field.
子选项len一个无符号整数，给出此子选项中子选项数据字段的长度（以八位字节为单位）。两个八位组的字段。
sub-option-data The data area for the sub-option. The length, in octets, is specified by sub-option-len.
子选项数据子选项的数据区域。长度（以八位字节为单位）由子选项len指定。
Multiple instances of the Vendor-specific Information option may appear in a DHCP message. Each instance of the option is interpreted according to the option codes defined by the vendor identified by the Enterprise Number in that option. Servers and clients MUST NOT send more than one instance of the Vendor-specific Information option with the same Enterprise Number. Each instance of the Vendor-specific Information option MAY contain multiple sub-options.
DHCP消息中可能会出现供应商特定信息选项的多个实例。该选项的每个实例都根据该选项中由企业编号标识的供应商定义的选项代码进行解释。服务器和客户端不得发送多个具有相同企业编号的供应商特定信息选项实例。供应商特定信息选项的每个实例可能包含多个子选项。
A client that is interested in receiving a Vendor-specific Information option:
有兴趣接收供应商特定信息选项的客户：
- MUST specify the Vendor-specific Information option in an Option Request option.
- 必须在选项请求选项中指定特定于供应商的信息选项。
- MAY specify an associated Vendor Class option (see Section 21.16).
- 可指定相关供应商类别选项（见第21.16节）。
- MAY specify the Vendor-specific Information option with appropriate data.
- 可以使用适当的数据指定特定于供应商的信息选项。
Servers only return the Vendor-specific Information options if specified in Option Request options from clients and:
如果在“来自客户端的选项请求选项”中指定，服务器仅返回特定于供应商的信息选项，并且：
- MAY use the Enterprise Numbers in the associated Vendor Class options to restrict the set of Enterprise Numbers in the Vendor-specific Information options returned.
- 可以使用相关供应商类别选项中的企业编号来限制返回的供应商特定信息选项中的企业编号集。
- MAY return all configured Vendor-specific Information options.
- 可以返回所有配置的供应商特定信息选项。
- MAY use other information in the packet or in its configuration to determine which set of Enterprise Numbers in the Vendor-specific Information options to return.
- 可以使用数据包或其配置中的其他信息来确定返回供应商特定信息选项中的哪组企业编号。
The relay agent MAY send the Interface-Id option to identify the interface on which the client message was received. If a relay agent receives a Relay-reply message with an Interface-Id option, the relay agent relays the message to the client through the interface identified by the option.
中继代理可以发送接口Id选项，以标识接收客户端消息的接口。如果中继代理接收到带有接口Id选项的中继回复消息，则中继代理将通过该选项标识的接口将消息中继到客户端。
The format of the Interface-Id option is:
接口Id选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_INTERFACE_ID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. interface-id .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_INTERFACE_ID | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. interface-id .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 32: Interface-Id Option Format
图32：接口Id选项格式
option-code OPTION_INTERFACE_ID (18).
选项代码选项接口ID（18）。
option-len Length of interface-id field.
选项len接口id字段的长度。
interface-id An opaque value of arbitrary length generated by the relay agent to identify one of the relay agent's interfaces. The length, in octets, is specified by option-len.
接口id中继代理生成的任意长度的不透明值，用于标识中继代理的一个接口。长度（以八位字节为单位）由选项len指定。
The server MUST copy the Interface-Id option from the Relay-forward message into the Relay-reply message the server sends to the relay agent in response to the Relay-forward message. This option MUST NOT appear in any message except a Relay-forward or Relay-reply message.
服务器必须将接口Id选项从中继转发消息复制到服务器发送给中继代理以响应中继转发消息的中继回复消息中。除中继转发或中继回复消息外，此选项不得出现在任何消息中。
Servers MAY use the interface-id field for parameter assignment policies. The interface-id value SHOULD be considered an opaque value, with policies based on exact match only; that is, the interface-id field SHOULD NOT be internally parsed by the server. The interface-id value for an interface SHOULD be stable and remain unchanged -- for example, after the relay agent is restarted; if the interface-id value changes, a server will not be able to use it reliably in parameter assignment policies.
服务器可以将接口id字段用于参数分配策略。接口id值应视为不透明值，策略仅基于精确匹配；也就是说，服务器不应在内部解析接口id字段。接口的接口id值应该是稳定的，并且保持不变——例如，在中继代理重新启动之后；如果接口id值更改，服务器将无法在参数分配策略中可靠地使用它。
A server includes a Reconfigure Message option in a Reconfigure message to indicate to the client whether the client responds with a Renew message, a Rebind message, or an Information-request message. The format of the Reconfigure Message option is:
服务器在重新配置消息中包括重新配置消息选项，以向客户端指示客户端是使用续订消息、重新绑定消息还是信息请求消息进行响应。“重新配置消息”选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RECONF_MSG | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type |
+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RECONF_MSG | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| msg-type |
+-+-+-+-+-+-+-+-+
Figure 33: Reconfigure Message Option Format
图33：重新配置消息选项格式
option-code OPTION_RECONF_MSG (19).
选项代码选项识别信息（19）。
option-len 1.
选项1。
msg-type 5 for Renew message, 6 for Rebind message, 11 for Information-request message. A 1-octet unsigned integer.
消息类型5表示续订消息，6表示重新绑定消息，11表示信息请求消息。一个1-octet无符号整数。
The Reconfigure Message option can only appear in a Reconfigure message.
重新配置消息选项只能出现在重新配置消息中。
A client uses the Reconfigure Accept option to announce to the server whether the client is willing to accept Reconfigure messages, and a server uses this option to tell the client whether or not to accept Reconfigure messages. In the absence of this option, the default behavior is that the client is unwilling to accept Reconfigure messages. The format of the Reconfigure Accept option is:
客户端使用重新配置接受选项向服务器宣布客户端是否愿意接受重新配置消息，服务器使用此选项告知客户端是否接受重新配置消息。如果没有此选项，默认行为是客户端不愿意接受重新配置消息。“重新配置接受”选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RECONF_ACCEPT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_RECONF_ACCEPT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 34: Reconfigure Accept Option Format
图34：重新配置接受选项格式
option-code OPTION_RECONF_ACCEPT (20).
选项代码选项重新确认接受（20）。
option-len 0.
选项len 0。
The IA_PD option is used to carry a prefix delegation identity association, the parameters associated with the IA_PD, and the prefixes associated with it. The format of the IA_PD option is:
IA_PD选项用于携带前缀委派标识关联、与IA_PD关联的参数以及与之关联的前缀。IA_PD选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_PD | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. IA_PD-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IA_PD | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IAID (4 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| T2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. IA_PD-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 35: Identity Association for Prefix Delegation Option Format
图35：前缀委派选项格式的标识关联
option-code OPTION_IA_PD (25).
选项代码选项IA_PD（25）。
option-len 12 + length of IA_PD-options field.
选项长度12+IA_PD-options字段的长度。
IAID The unique identifier for this IA_PD; the IAID must be unique among the identifiers for all of this client's IA_PDs. The number space for IA_PD IAIDs is separate from the number space for other IA option types (i.e., IA_NA and IA_TA). A 4-octet field containing an unsigned integer.
IAID此IA_PD的唯一标识符；IAID在该客户端的所有IA_PDs的标识符中必须是唯一的。IA_PD IAID的数字空间与其他IA选项类型（即IA_NA和IA_TA）的数字空间是分开的。包含无符号整数的4个八位字段。
T1 The time interval after which the client should contact the server from which the prefixes in the IA_PD were obtained to extend the lifetimes of the prefixes delegated to the IA_PD; T1 is a time duration relative to the message reception time expressed in units of seconds. A 4-octet field containing an unsigned integer.
T1时间间隔，在此时间间隔之后，客户端应联系从中获取IA_PD中前缀的服务器，以延长委派给IA_PD的前缀的生命周期；T1是相对于以秒为单位表示的消息接收时间的持续时间。包含无符号整数的4个八位字段。
T2 The time interval after which the client should contact any available server to extend the lifetimes of the prefixes assigned to the IA_PD; T2 is a time duration relative to the message reception time expressed in units of seconds. A 4-octet field containing an unsigned integer.
T2客户端应联系任何可用服务器以延长分配给IA_PD的前缀的生存期的时间间隔；T2是相对于以秒为单位表示的消息接收时间的持续时间。包含无符号整数的4个八位字段。
IA_PD-options Options associated with this IA_PD. A variable-length field (12 octets less than the value in the option-len field).
IA_PD—与此IA_PD关联的选项。可变长度字段（比选项len字段中的值小12个八位字节）。
The IA_PD-options field encapsulates those options that are specific to this IA_PD. For example, all of the IA Prefix options (see Section 21.22) carrying the prefixes associated with this IA_PD are in the IA_PD-options field.
IA_PD-options字段封装了特定于此IA_PD的选项。例如，所有带有与此IA_PD相关前缀的IA前缀选项（参见第21.22节）都位于IA_PD-options字段中。
An IA_PD option may only appear in the options area of a DHCP message. A DHCP message may contain multiple IA_PD options (though each must have a unique IAID).
IA_PD选项只能出现在DHCP消息的选项区域中。DHCP消息可能包含多个IA_PD选项（尽管每个选项必须具有唯一的IAID）。
The status of any operations involving this IA_PD is indicated in a Status Code option (see Section 21.13) in the IA_PD-options field.
涉及此IA_PD的任何操作的状态在IA_PD-options字段中的状态代码选项（见第21.13节）中指示。
Note that an IA_PD has no explicit "lifetime" or "lease length" of its own. When the valid lifetimes of all of the prefixes in an IA_PD have expired, the IA_PD can be considered as having expired. T1 and T2 fields are included to give the server explicit control over when a client should contact the server about a specific IA_PD.
请注意，IA_PD本身没有明确的“寿命”或“租赁期限”。当IA_PD中所有前缀的有效生存期已过期时，可以认为IA_PD已过期。T1和T2字段用于让服务器明确控制客户端何时应就特定IA_PD联系服务器。
In a message sent by a client to a server, the T1 and T2 fields SHOULD be set to 0. The server MUST ignore any values in these fields in messages received from a client.
在客户端发送到服务器的消息中，T1和T2字段应设置为0。服务器必须忽略从客户端接收的消息中这些字段中的任何值。
In a message sent by a server to a client, the client MUST use the values in the T1 and T2 fields for the T1 and T2 timers, unless values in those fields are 0. The values in the T1 and T2 fields are the number of seconds until T1 and T2.
在服务器发送给客户机的消息中，客户机必须为T1和T2计时器使用T1和T2字段中的值，除非这些字段中的值为0。T1和T2字段中的值是T1和T2之前的秒数。
The server selects the T1 and T2 times to allow the client to extend the lifetimes of any prefixes in the IA_PD before the lifetimes expire, even if the server is unavailable for some short period of time. Recommended values for T1 and T2 are 0.5 and 0.8 times the shortest preferred lifetime of the prefixes in the IA_PD that the server is willing to extend, respectively. If the time at which the prefixes in an IA_PD are to be renewed is to be left to the discretion of the client, the server sets T1 and T2 to 0. The client MUST follow the rules defined in Section 14.2.
服务器选择T1和T2时间，以允许客户端在生命周期到期之前延长IA_PD中任何前缀的生命周期，即使服务器在短时间内不可用。T1和T2的建议值分别是服务器愿意延长的IA_PD中前缀的最短首选生存期的0.5倍和0.8倍。如果IA_PD中前缀的更新时间由客户端决定，则服务器将T1和T2设置为0。客户必须遵守第14.2节规定的规则。
If a client receives an IA_PD with T1 greater than T2 and both T1 and T2 are greater than 0, the client discards the IA_PD option and processes the remainder of the message as though the server had not included the IA_PD option.
如果客户端接收到T1大于T2的IA_PD，并且T1和T2都大于0，则客户端将丢弃IA_PD选项并处理消息的其余部分，就像服务器未包含IA_PD选项一样。
The IA Prefix option is used to specify a prefix associated with an IA_PD. The IA Prefix option must be encapsulated in the IA_PD-options field of an IA_PD option (see Section 21.21).
IA Prefix选项用于指定与IA_PD关联的前缀。IA前缀选项必须封装在IA_PD选项的IA_PD-options字段中（见第21.21节）。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IAPREFIX | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| preferred-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| valid-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| prefix-length | |
+-+-+-+-+-+-+-+-+ IPv6-prefix |
| (16 octets) |
| |
| |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | .
+-+-+-+-+-+-+-+-+ .
. IAprefix-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_IAPREFIX | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| preferred-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| valid-lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| prefix-length | |
+-+-+-+-+-+-+-+-+ IPv6-prefix |
| (16 octets) |
| |
| |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | .
+-+-+-+-+-+-+-+-+ .
. IAprefix-options .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 36: IA Prefix Option Format
图36:IA前缀选项格式
option-code OPTION_IAPREFIX (26).
选项代码选项前缀（26）。
option-len 25 + length of IAprefix-options field.
选项长度25+IAprefix选项字段的长度。
preferred-lifetime The preferred lifetime for the prefix in the option, expressed in units of seconds. A value of 0xffffffff represents "infinity" (see Section 7.7). A 4-octet field containing an unsigned integer.
首选生存期选项中前缀的首选生存期，以秒为单位。0xFFFFFF的值表示“无穷大”（参见第7.7节）。包含无符号整数的4个八位字段。
valid-lifetime The valid lifetime for the prefix in the option, expressed in units of seconds. A value of 0xffffffff represents "infinity". A 4-octet field containing an unsigned integer.
有效生存期选项中前缀的有效生存期，以秒为单位。0xFFFFFF的值表示“无穷大”。包含无符号整数的4个八位字段。
prefix-length Length for this prefix in bits. A 1-octet unsigned integer.
前缀长度此前缀的长度（以位为单位）。一个1-octet无符号整数。
IPv6-prefix An IPv6 prefix. A 16-octet field.
IPv6前缀IPv6前缀。16个八位组的字段。
IAprefix-options Options associated with this prefix. A variable-length field (25 octets less than the value in the option-len field).
IAprefix选项与此前缀关联的选项。可变长度字段（比选项len字段中的值小25个八位字节）。
In a message sent by a client to a server, the preferred-lifetime and valid-lifetime fields SHOULD be set to 0. The server MUST ignore any received values in these lifetime fields.
在客户端发送到服务器的消息中，首选生存期和有效生存期字段应设置为0。服务器必须忽略这些生存期字段中收到的任何值。
The client SHOULD NOT send an IA Prefix option with 0 in the "prefix-length" field (and an unspecified value (::) in the "IPv6-prefix" field). A client MAY send a non-zero value in the "prefix-length" field and the unspecified value (::) in the "IPv6-prefix" field to indicate a preference for the size of the prefix to be delegated. See [RFC8168] for further details on prefix-length hints.
客户端不应发送“前缀长度”字段中为0的IA前缀选项（以及“IPv6前缀”字段中未指定的值（：：）。客户端可以在“前缀长度”字段中发送非零值，在“IPv6前缀”字段中发送未指定的值（：：），以指示要委派的前缀大小的首选项。有关前缀长度提示的更多详细信息，请参阅[RFC8168]。
The client MUST discard any prefixes for which the preferred lifetime is greater than the valid lifetime.
客户端必须丢弃首选生存期大于有效生存期的任何前缀。
The values in the preferred-lifetime and valid-lifetime fields are the number of seconds remaining in each lifetime. See Section 18.2.10.1 for more details on how these values are used for delegated prefixes.
首选生存期和有效生存期字段中的值是每个生存期中剩余的秒数。有关如何将这些值用于委派前缀的更多详细信息，请参见第18.2.10.1节。
As per Section 7.7, the value of 0xffffffff for the preferred lifetime or the valid lifetime is taken to mean "infinity" and should be used carefully.
根据第7.7节，优选寿命或有效寿命的0xFFFFFF值被视为“无穷大”，应谨慎使用。
An IA Prefix option may appear only in an IA_PD option. More than one IA Prefix option can appear in a single IA_PD option.
IA前缀选项只能出现在IA_PD选项中。单个IA_PD选项中可以出现多个IA前缀选项。
The status of any operations involving this IA Prefix option is indicated in a Status Code option (see Section 21.13) in the IAprefix-options field.
涉及此IA前缀选项的任何操作的状态在IAprefix选项字段中的状态代码选项（见第21.13节）中指示。
This option is requested by clients and returned by servers to specify an upper bound for how long a client should wait before refreshing information retrieved from a DHCP server. It is only used in Reply messages in response to Information-request messages. In other messages, there will usually be other information that indicates when the client should contact the server, e.g., T1/T2 times and lifetimes. This option is useful when the configuration parameters change or during a renumbering event, as clients running in the stateless mode will be able to update their configuration.
此选项由客户端请求并由服务器返回，以指定客户端在刷新从DHCP服务器检索的信息之前应等待的时间上限。它仅用于响应信息请求消息的回复消息。在其他消息中，通常会有其他信息指示客户端何时应联系服务器，例如T1/T2时间和生存时间。当配置参数更改或在重新编号事件期间，此选项非常有用，因为在无状态模式下运行的客户端将能够更新其配置。
The format of the Information Refresh Time option is:
信息刷新时间选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|OPTION_INFORMATION_REFRESH_TIME| option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| information-refresh-time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|OPTION_INFORMATION_REFRESH_TIME| option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| information-refresh-time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 37: Information Refresh Time Option Format
图37：信息刷新时间选项格式
option-code OPTION_INFORMATION_REFRESH_TIME (32).
选项代码选项信息刷新时间（32）。
option-len 4.
选项4。
information-refresh-time Time duration relative to the current time, expressed in units of seconds. A 4-octet field containing an unsigned integer.
信息刷新时间相对于当前时间的持续时间，以秒为单位。包含无符号整数的4个八位字段。
A DHCP client MUST request this option in the Option Request option (see Section 21.7) when sending Information-request messages. A client MUST NOT request this option in the Option Request option in any other messages.
DHCP客户端在发送信息请求消息时，必须在选项请求选项（参见第21.7节）中请求此选项。客户端不得在任何其他消息的选项请求选项中请求此选项。
A server sending a Reply to an Information-request message SHOULD include this option if it is requested in the Option Request option of the Information-request. The option value MUST NOT be smaller than IRT_MINIMUM. This option MUST only appear in the top-level options area of Reply messages.
如果在信息请求的选项“请求”选项中请求回复，则发送回复信息请求消息的服务器应包含此选项。选项值不得小于IRT_最小值。此选项只能出现在回复消息的顶级选项区域中。
If the Reply to an Information-request message does not contain this option, the client MUST behave as if the option with the value IRT_DEFAULT was provided.
如果对信息请求消息的回复不包含此选项，则客户端必须表现为提供了值为IRT_DEFAULT的选项。
A client MUST use the refresh time IRT_MINIMUM if it receives the option with a value less than IRT_MINIMUM.
如果客户端收到的选项值小于IRT_最小值，则必须使用刷新时间IRT_最小值。
As per Section 7.7, the value 0xffffffff is taken to mean "infinity" and implies that the client should not refresh its configuration data without some other trigger (such as detecting movement to a new link).
根据第7.7节，值0xFFFFFF表示“无穷大”，并表示客户端不应在没有其他触发（如检测到新链接的移动）的情况下刷新其配置数据。
If a client contacts the server to obtain new data or refresh some existing data before the refresh time expires, then it SHOULD also refresh all data covered by this option.
如果客户机在刷新时间到期之前联系服务器以获取新数据或刷新某些现有数据，则它还应刷新此选项涵盖的所有数据。
When the client detects that the refresh time has expired, it SHOULD try to update its configuration data by sending an Information-request as specified in Section 18.2.6, except that the client MUST delay sending the first Information-request by a random amount of time between 0 and INF_MAX_DELAY.
当客户机检测到刷新时间已过期时，应尝试通过发送第18.2.6节中规定的信息请求来更新其配置数据，但客户机必须将发送第一个信息请求的时间延迟0到INF_MAX_delay之间的随机时间量。
A client MAY have a maximum value for the refresh time, where that value is used whenever the client receives this option with a value higher than the maximum. This also means that the maximum value is used when the received value is "infinity". A maximum value might make the client less vulnerable to attacks based on forged DHCP messages. Without a maximum value, a client may be made to use wrong information for a possibly infinite period of time. There may, however, be reasons for having a very long refresh time, so it may be useful for this maximum value to be configurable.
客户机可能具有刷新时间的最大值，每当客户机接收到该选项的值高于最大值时，就会使用该值。这也意味着，当接收值为“无穷大”时，使用最大值。最大值可能使客户端不易受到基于伪造DHCP消息的攻击。如果没有最大值，客户可能会在无限的时间内使用错误的信息。但是，刷新时间很长可能是有原因的，因此可配置此最大值可能很有用。
A DHCP server sends the SOL_MAX_RT option to a client to override the default value of SOL_MAX_RT. The value of SOL_MAX_RT in the option replaces the default value defined in Section 7.6. One use for the SOL_MAX_RT option is to set a higher value for SOL_MAX_RT; this reduces the Solicit traffic from a client that has not received a response to its Solicit messages.
DHCP服务器向客户端发送SOL_MAX_RT选项，以覆盖SOL_MAX_RT的默认值。该选项中的SOL_MAX_RT值替换第7.6节中定义的默认值。SOL_MAX_RT选项的一个用途是为SOL_MAX_RT设置更高的值；这将减少来自尚未收到请求消息响应的客户端的请求流量。
The format of the SOL_MAX_RT option is:
SOL_MAX_RT选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_SOL_MAX_RT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SOL_MAX_RT value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_SOL_MAX_RT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SOL_MAX_RT value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 38: SOL_MAX_RT Option Format
图38:SOL_MAX_RT选项格式
option-code OPTION_SOL_MAX_RT (82).
选项代码选项\u SOL\u MAX\u RT（82）。
option-len 4.
选项4。
SOL_MAX_RT value Overriding value for SOL_MAX_RT in seconds; MUST be in this range: 60 <= "value" <= 86400 (1 day). A 4-octet field containing an unsigned integer.
SOL_MAX_RT值覆盖SOL_MAX_RT的值（秒）；必须在此范围内：60<=“值”<=86400（1天）。包含无符号整数的4个八位字段。
A DHCP client MUST include the SOL_MAX_RT option code in any Option Request option (see Section 21.7) it sends in a Solicit message.
DHCP客户端必须在其在请求消息中发送的任何选项请求选项（参见第21.7节）中包含SOL_MAX_RT选项代码。
The DHCP server MAY include the SOL_MAX_RT option in any response it sends to a client that has included the SOL_MAX_RT option code in an Option Request option. The SOL_MAX_RT option is sent as a top-level option in the message to the client.
DHCP服务器可以在发送给已在选项请求选项中包含SOL_MAX_RT选项代码的客户端的任何响应中包含SOL_MAX_RT选项。SOL_MAX_RT选项作为消息中的顶级选项发送到客户端。
A DHCP client MUST ignore any SOL_MAX_RT option values that are less than 60 or more than 86400.
DHCP客户端必须忽略任何小于60或大于86400的SOL_MAX_RT选项值。
If a DHCP client receives a message containing a SOL_MAX_RT option that has a valid value for SOL_MAX_RT, the client MUST set its internal SOL_MAX_RT parameter to the value contained in the SOL_MAX_RT option. This value of SOL_MAX_RT is then used by the retransmission mechanism defined in Sections 15 and 18.2.1.
如果DHCP客户端收到包含SOL_MAX_RT选项的消息，该选项具有SOL_MAX_RT的有效值，则客户端必须将其内部SOL_MAX_RT参数设置为SOL_MAX_RT选项中包含的值。然后，第15节和第18.2.1节中定义的重传机制使用该SOL_MAX_RT值。
The purpose of this mechanism is to give network administrators a way to avoid excessive DHCP traffic if all DHCP servers become unavailable. Therefore, this value is expected to be retained for as long as practically possible.
此机制的目的是为网络管理员提供一种在所有DHCP服务器都不可用时避免过多DHCP流量的方法。因此，预计该值将保留尽可能长的时间。
An updated SOL_MAX_RT value applies only to the network interface on which the client received the SOL_MAX_RT option.
更新的SOL_MAX_RT值仅适用于客户端接收SOL_MAX_RT选项的网络接口。
A DHCP server sends the INF_MAX_RT option to a client to override the default value of INF_MAX_RT. The value of INF_MAX_RT in the option replaces the default value defined in Section 7.6. One use for the INF_MAX_RT option is to set a higher value for INF_MAX_RT; this reduces the Information-request traffic from a client that has not received a response to its Information-request messages.
DHCP服务器将INF_MAX_RT选项发送给客户端，以覆盖INF_MAX_RT的默认值。该选项中的INF_MAX_RT值将替换第7.6节中定义的默认值。INF\u MAX\u RT选项的一个用途是为INF\u MAX\u RT设置更高的值；这减少了来自尚未收到对其信息请求消息的响应的客户端的信息请求流量。
The format of the INF_MAX_RT option is:
INF\u MAX\u RT选项的格式为：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_INF_MAX_RT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INF_MAX_RT value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_INF_MAX_RT | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INF_MAX_RT value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 39: INF_MAX_RT Option Format
图39:INF\U MAX\U RT选项格式
option-code OPTION_INF_MAX_RT (83).
选项代码选项INF\u MAX\u RT（83）。
option-len 4.
选项4。
INF_MAX_RT value Overriding value for INF_MAX_RT in seconds; MUST be in this range: 60 <= "value" <= 86400 (1 day). A 4-octet field containing an unsigned integer.
INF\u MAX\u RT值覆盖INF\u MAX\u RT的值（秒）；必须在此范围内：60<=“值”<=86400（1天）。包含无符号整数的4个八位字段。
A DHCP client MUST include the INF_MAX_RT option code in any Option Request option (see Section 21.7) it sends in an Information-request message.
DHCP客户端必须在其在信息请求消息中发送的任何选项请求选项（见第21.7节）中包含INF\u MAX\u RT选项代码。
The DHCP server MAY include the INF_MAX_RT option in any response it sends to a client that has included the INF_MAX_RT option code in an Option Request option. The INF_MAX_RT option is a top-level option in the message to the client.
DHCP服务器可以在发送给已在选项请求选项中包含INF\u MAX\u RT选项代码的客户端的任何响应中包含INF\u MAX\u RT选项。INF\u MAX\u RT选项是发送给客户端的消息中的顶级选项。
A DHCP client MUST ignore any INF_MAX_RT option values that are less than 60 or more than 86400.
DHCP客户端必须忽略任何小于60或大于86400的INF_MAX_RT选项值。
If a DHCP client receives a message containing an INF_MAX_RT option that has a valid value for INF_MAX_RT, the client MUST set its internal INF_MAX_RT parameter to the value contained in the INF_MAX_RT option. This value of INF_MAX_RT is then used by the retransmission mechanism defined in Sections 15 and 18.2.6.
如果DHCP客户端接收到包含INF\u MAX\u RT选项的消息，该选项具有INF\u MAX\u RT的有效值，则客户端必须将其内部INF\u MAX\u RT参数设置为INF\u MAX\u RT选项中包含的值。该INF_MAX_RT值随后由第15节和第18.2.6节中定义的重传机制使用。
An updated INF_MAX_RT value applies only to the network interface on which the client received the INF_MAX_RT option.
更新的INF_MAX_RT值仅适用于客户端接收INF_MAX_RT选项的网络接口。
This section discusses security considerations that are not related to privacy. See Section 23 for a discussion dedicated to privacy.
本节讨论与隐私无关的安全注意事项。有关隐私的讨论，请参见第23节。
The threat to DHCP is inherently an insider threat (assuming a properly configured network where DHCP ports are blocked on the perimeter gateways of the enterprise). Regardless of the gateway configuration, however, the potential attacks by insiders and outsiders are the same.
对DHCP的威胁本质上是内部威胁（假设一个配置正确的网络，其中DHCP端口在企业的外围网关上被阻塞）。但是，无论网关配置如何，内部人员和外部人员的潜在攻击都是相同的。
DHCP lacks end-to-end encryption between clients and servers; thus, hijacking, tampering, and eavesdropping attacks are all possible as a result. Some network environments (discussed below) can be secured through various means to minimize these attacks.
DHCP缺少客户端和服务器之间的端到端加密；因此，劫持、篡改和窃听攻击都是可能的。一些网络环境（下文讨论）可以通过各种方式进行安全保护，以最大限度地减少这些攻击。
One attack specific to a DHCP client is the establishment of a malicious server with the intent of providing incorrect configuration information to the client. The motivation for doing so may be to mount a "man in the middle" attack that causes the client to communicate with a malicious server instead of a valid server for some service (such as DNS or NTP). The malicious server may also mount a DoS attack through misconfiguration of the client; this attack would cause all network communication from the client to fail.
针对DHCP客户端的一种攻击是建立恶意服务器，目的是向客户端提供不正确的配置信息。这样做的动机可能是装载“中间人”攻击，导致客户端与恶意服务器通信，而不是与某些服务（如DNS或NTP）的有效服务器通信。恶意服务器还可能通过错误配置客户端而发起DoS攻击；此攻击将导致客户端的所有网络通信失败。
A malicious DHCP server might cause a client to set its SOL_MAX_RT and INF_MAX_RT parameters to an unreasonably high value with the SOL_MAX_RT (see Section 21.24) and INF_MAX_RT (see Section 21.25) options; this may cause an undue delay in a client completing its DHCP protocol transaction in the case where no other valid response is received. Assuming that the client also receives a response from a valid DHCP server, large values for SOL_MAX_RT and INF_MAX_RT will not have any effect.
恶意DHCP服务器可能会导致客户端使用SOL_MAX_RT（参见第21.24节）和INF_MAX_RT（参见第21.25节）选项将其SOL_MAX_RT和INF_MAX_RT参数设置为不合理的高值；在没有收到其他有效响应的情况下，这可能会导致客户端在完成其DHCP协议事务时出现不适当的延迟。假设客户端也从有效的DHCP服务器接收到响应，则SOL_MAX_RT和INF_MAX_RT的大值将不会产生任何影响。
A malicious server can also send a Server Unicast option (see Section 21.12) to a client in an Advertise message, thus potentially causing the client to bypass relays and communicate only with the malicious server for subsequent Request and Renew messages.
恶意服务器还可以在播发消息中向客户端发送服务器单播选项（请参见第21.12节），从而可能导致客户端绕过中继，仅与恶意服务器通信以获取后续请求和续订消息。
Another threat to DHCP clients originates from mistakenly or accidentally configured DHCP servers that answer DHCP client requests with unintentionally incorrect configuration parameters.
DHCP客户端的另一个威胁源于错误或意外配置的DHCP服务器，这些服务器使用不正确的配置参数响应DHCP客户端请求。
A DHCP client may also be subject to attack through the receipt of a Reconfigure message from a malicious server that causes the client to obtain incorrect configuration information from that server. Note that although a client sends its response (Renew, Rebind, or Information-request message) through a relay agent and, therefore,
DHCP客户端还可能通过从恶意服务器接收重新配置消息而受到攻击，该消息会导致客户端从该服务器获取不正确的配置信息。请注意，尽管客户端通过中继代理发送其响应（续订、重新绑定或信息请求消息），因此，
that response will only be received by servers to which DHCP messages are relayed, a malicious server could send a Reconfigure message to a client, followed (after an appropriate delay) by a Reply message that would be accepted by the client. Thus, a malicious server that is not on the network path between the client and the server may still be able to mount a Reconfigure attack on a client. The use of transaction IDs that are cryptographically sound and cannot easily be predicted will also reduce the probability that such an attack will be successful.
该响应将仅由DHCP消息中继到的服务器接收，恶意服务器可能会向客户端发送重新配置消息，然后（在适当延迟后）发送客户端将接受的回复消息。因此，不在客户端和服务器之间的网络路径上的恶意服务器可能仍然能够在客户端上装载重新配置攻击。使用加密可靠且不易预测的事务ID也将降低此类攻击成功的概率。
Because of the opportunity for attack through the Reconfigure message, a DHCP client MUST discard any Reconfigure message that does not include authentication or that does not pass the validation process for the authentication protocol.
由于存在通过重新配置消息进行攻击的机会，DHCP客户端必须丢弃任何不包含身份验证或未通过身份验证协议验证过程的重新配置消息。
RKAP, described in Section 20.4, provides protection against the use of a Reconfigure message by a malicious DHCP server to mount a DoS or man-in-the-middle attack on a client. This protocol can be compromised by an attacker that can intercept the initial message in which the DHCP server sends the key "in plain text" to the client.
第20.4节中描述的RKAP提供保护，防止恶意DHCP服务器使用重新配置消息在客户端上装载DoS或中间人攻击。攻击者可以截获DHCP服务器向客户端发送“纯文本”密钥的初始消息，从而破坏该协议。
Many of these attacks by rogue servers can be mitigated by making use of the mechanisms described in [RFC7610] and [RFC7513].
通过使用[RFC7610]和[RFC7513]中描述的机制，可以减轻流氓服务器的许多攻击。
The threat specific to a DHCP server is an invalid client masquerading as a valid client. The motivation for this may be for theft of service, or to circumvent auditing for any number of nefarious purposes.
DHCP服务器特有的威胁是伪装为有效客户端的无效客户端。这样做的动机可能是为了窃取服务，或为了任何邪恶目的规避审计。
The threat common to both the client and the server is the "resource-exhaustion" DoS attack. These attacks typically involve the exhaustion of available assigned addresses or delegatable prefixes, or the exhaustion of CPU or network bandwidth, and are present any time there is a shared resource. Some forms of these exhaustion attacks can be partially mitigated by appropriate server policy, e.g., limiting the maximum number of leases any one client can get.
客户端和服务器共同面临的威胁是“资源耗尽”DoS攻击。这些攻击通常涉及可用分配地址或可删除前缀的耗尽，或CPU或网络带宽的耗尽，并且在存在共享资源时随时存在。这些耗尽攻击的某些形式可以通过适当的服务器策略部分缓解，例如，限制任何一个客户端可以获得的最大租约数。
The messages exchanged between relay agents and servers may be used to mount a man-in-the-middle or DoS attack. Communication between a server and a relay agent, and communication between relay agents, can be authenticated and encrypted through the use of IPsec, as described in [RFC8213].
中继代理和服务器之间交换的消息可用于发起中间人攻击或DoS攻击。服务器和中继代理之间的通信以及中继代理之间的通信可以通过使用IPsec进行身份验证和加密，如[RFC8213]中所述。
However, the use of manually configured pre-shared keys for IPsec between relay agents and servers does not defend against replayed DHCP messages. Replayed messages can represent a DoS attack through exhaustion of processing resources but not through misconfiguration or exhaustion of other resources such as assignable addresses and delegatable prefixes.
但是，在中继代理和服务器之间为IPsec使用手动配置的预共享密钥并不能防止重播DHCP消息。重放的消息可能通过耗尽处理资源而不是通过错误配置或耗尽其他资源（如可分配地址和可委派前缀）来表示DoS攻击。
Various network environments also offer levels of security if deployed as described below.
如果按如下所述部署，各种网络环境也提供了安全级别。
- In enterprise and factory networks, use of authentication per [IEEE-802.1x] can prevent unknown or untrusted clients from connecting to the network. However, this does not necessarily assure that the connected client will be a good DHCP or network actor.
- 在企业和工厂网络中，根据[IEEE-802.1x]使用身份验证可以防止未知或不受信任的客户端连接到网络。然而，这并不一定能保证连接的客户端是一个好的DHCP或网络参与者。
- For wired networks where clients typically are connected to a switch port, snooping DHCP multicast (or unicast) traffic becomes difficult, as the switches limit the traffic delivered to a port. The client's DHCP multicast packets (with destination address fe02::1:2) are only forwarded to the DHCP server's (or relay's) switch port -- not all ports. Also, the server's (or relay's) unicast replies are only delivered to the target client's port -- not all ports.
- 对于客户端通常连接到交换机端口的有线网络，监听DHCP多播（或单播）流量变得很困难，因为交换机限制了传输到端口的流量。客户端的DHCP多播数据包（目标地址为fe02:：1:2）仅转发到DHCP服务器（或中继）的交换机端口，而不是所有端口。此外，服务器（或中继）的单播回复只发送到目标客户端的端口，而不是所有端口。
- In public networks (such as a Wi-Fi network in a coffee shop or airport), it is possible for others within radio range to snoop DHCP and other traffic. But in these environments, there is very little if anything that can be learned from the DHCP traffic itself (either from client to server or from server to client) if the privacy considerations provided in Section 23 are followed. Even for devices that do not follow the privacy considerations, there is little that can be learned that would not be available from subsequent communications anyway (such as the device's Media Access Control (MAC) address). Also, because all clients will typically receive similar configuration details, a bad actor that initiates a DHCP request itself can learn much of such information. As mentioned above, one threat is that the RKAP key for a client can be learned (if the initial Solicit/Advertise/Request/Reply exchange is monitored) and trigger a premature reconfiguration, but this is relatively easily prevented by disallowing direct client-to-client communication on these networks or using [RFC7610] and [RFC7513].
- 在公共网络（如咖啡店或机场的Wi-Fi网络）中，无线电范围内的其他人可能窥探DHCP和其他流量。但是，在这些环境中，如果遵循第23节中提供的隐私注意事项，那么从DHCP通信本身（从客户端到服务器或从服务器到客户端）了解到的信息就很少。即使对于不遵循隐私考虑的设备，也没有什么可以从后续通信（如设备的媒体访问控制（MAC）地址）中了解到的信息。此外，由于所有客户机通常都会收到类似的配置详细信息，因此发起DHCP请求的坏参与者本身可以了解很多此类信息。如上所述，一个威胁是可以学习客户端的RKAP密钥（如果监视初始请求/广告/请求/应答交换）并触发过早的重新配置，但是通过禁止这些网络上的直接客户端到客户端通信或使用[RFC7610]和[RFC7513]可以相对容易地防止这种情况。
For an extended discussion about privacy considerations for the client, see [RFC7824]:
有关客户端隐私注意事项的详细讨论，请参阅[RFC7824]：
- In particular, its Section 3 discusses various identifiers that could be misused to track the client.
- 特别是，其第3节讨论了可能被误用来跟踪客户机的各种标识符。
- Its Section 4 discusses existing mechanisms that may have an impact on a client's privacy.
- 第4节讨论了可能影响客户隐私的现有机制。
- Finally, its Section 5 discusses potential attack vectors.
- 最后，第5节讨论了潜在的攻击向量。
For recommendations regarding how to address or mitigate those issues, see [RFC7844].
有关如何解决或缓解这些问题的建议，请参阅[RFC7844]。
This specification does not define any allocation strategies for servers. Implementers are expected to develop their own algorithm for the server to choose a resource out of the available pool. Several possible allocation strategies are mentioned in Section 4.3 of [RFC7824]. Please keep in mind that the list in [RFC7824] is not exhaustive; there are certainly other possible strategies. Readers are also encouraged to read [RFC7707] -- in particular, its Section 4.1.2, which discusses the problems with certain allocation strategies.
本规范未定义服务器的任何分配策略。实现者需要为服务器开发自己的算法，以便从可用池中选择资源。[RFC7824]第4.3节中提到了几种可能的分配策略。请记住，[RFC7824]中的列表并非详尽无遗；当然还有其他可能的策略。还鼓励读者阅读[RFC7707]——特别是第4.1.2节，其中讨论了某些分配策略的问题。
This document does not define any new DHCP name spaces or definitions.
本文档不定义任何新的DHCP名称空间或定义。
The publication of this document does not change the assignment rules for new values for message types, option codes, DUID types, or status codes.
本文档的发布不会更改消息类型、选项代码、DUID类型或状态代码的新值的分配规则。
The list of assigned values used in DHCPv6 is available at <https://www.iana.org/assignments/dhcpv6-parameters>.
DHCPv6中使用的赋值列表可在<https://www.iana.org/assignments/dhcpv6-parameters>.
IANA has updated <https://www.iana.org/assignments/dhcpv6-parameters> to add a reference to this document for definitions previously created by [RFC3315], [RFC3633], [RFC4242], and [RFC7083].
IANA已更新<https://www.iana.org/assignments/dhcpv6-parameters>为之前由[RFC3315]、[RFC3633]、[RFC4242]和[RFC7083]创建的定义添加本文件参考。
IANA has added two columns to the DHCPv6 "Option Codes" registry at
<https://www.iana.org/assignments/dhcpv6-parameters> to indicate
which options are allowed to appear in a client's Option Request
option (see Section 21.7) and which options are singleton options
IANA has added two columns to the DHCPv6 "Option Codes" registry at
<https://www.iana.org/assignments/dhcpv6-parameters> to indicate
which options are allowed to appear in a client's Option Request
option (see Section 21.7) and which options are singleton options
(only allowed to appear once as a top-level or encapsulated option; see Section 16 of [RFC7227]). Table 4 provides the data for the options assigned by IANA at the time of writing this document.
（仅允许作为顶级或封装选项出现一次；请参见[RFC7227]第16节）。表4提供了编写本文件时IANA分配的选项数据。
+---------+--------------------------+------------------+-----------+
| Option | Option Name ("OPTION" | Client ORO (1) | Singleton |
| | prefix removed) | | Option |
+---------+--------------------------+------------------+-----------+
| 1 | CLIENTID | No | Yes |
| 2 | SERVERID | No | Yes |
| 3 | IA_NA | No | No |
| 4 | IA_TA | No | No |
| 5 | IAADDR | No | No |
| 6 | ORO | No | Yes |
| 7 | PREFERENCE | No | Yes |
| 8 | ELAPSED_TIME | No | Yes |
| 9 | RELAY_MSG | No | Yes |
| 11 | AUTH | No | Yes |
| 12 | UNICAST | No | Yes |
| 13 | STATUS_CODE | No | Yes |
| 14 | RAPID_COMMIT | No | Yes |
| 15 | USER_CLASS | No | Yes |
| 16 | VENDOR_CLASS | No | No (2) |
| 17 | VENDOR_OPTS | Optional | No (2) |
| 18 | INTERFACE_ID | No | Yes |
| 19 | RECONF_MSG | No | Yes |
| 20 | RECONF_ACCEPT | No | Yes |
| 21 | SIP_SERVER_D | Yes | Yes |
| 22 | SIP_SERVER_A | Yes | Yes |
| 23 | DNS_SERVERS | Yes | Yes |
| 24 | DOMAIN_LIST | Yes | Yes |
| 25 | IA_PD | No | No |
| 26 | IAPREFIX | No | No |
| 27 | NIS_SERVERS | Yes | Yes |
| 28 | NISP_SERVERS | Yes | Yes |
| 29 | NIS_DOMAIN_NAME | Yes | Yes |
| 30 | NISP_DOMAIN_NAME | Yes | Yes |
| 31 | SNTP_SERVERS | Yes | Yes |
| 32 | INFORMATION_REFRESH_TIME | Required for | Yes |
| | | Information- | |
| | | request | |
| 33 | BCMCS_SERVER_D | Yes | Yes |
| 34 | BCMCS_SERVER_A | Yes | Yes |
| 36 | GEOCONF_CIVIC | Yes | Yes |
| 37 | REMOTE_ID | No | Yes |
| 38 | SUBSCRIBER_ID | No | Yes |
| 39 | CLIENT_FQDN | Yes | Yes |
| 40 | PANA_AGENT | Yes | Yes |
+---------+--------------------------+------------------+-----------+
| Option | Option Name ("OPTION" | Client ORO (1) | Singleton |
| | prefix removed) | | Option |
+---------+--------------------------+------------------+-----------+
| 1 | CLIENTID | No | Yes |
| 2 | SERVERID | No | Yes |
| 3 | IA_NA | No | No |
| 4 | IA_TA | No | No |
| 5 | IAADDR | No | No |
| 6 | ORO | No | Yes |
| 7 | PREFERENCE | No | Yes |
| 8 | ELAPSED_TIME | No | Yes |
| 9 | RELAY_MSG | No | Yes |
| 11 | AUTH | No | Yes |
| 12 | UNICAST | No | Yes |
| 13 | STATUS_CODE | No | Yes |
| 14 | RAPID_COMMIT | No | Yes |
| 15 | USER_CLASS | No | Yes |
| 16 | VENDOR_CLASS | No | No (2) |
| 17 | VENDOR_OPTS | Optional | No (2) |
| 18 | INTERFACE_ID | No | Yes |
| 19 | RECONF_MSG | No | Yes |
| 20 | RECONF_ACCEPT | No | Yes |
| 21 | SIP_SERVER_D | Yes | Yes |
| 22 | SIP_SERVER_A | Yes | Yes |
| 23 | DNS_SERVERS | Yes | Yes |
| 24 | DOMAIN_LIST | Yes | Yes |
| 25 | IA_PD | No | No |
| 26 | IAPREFIX | No | No |
| 27 | NIS_SERVERS | Yes | Yes |
| 28 | NISP_SERVERS | Yes | Yes |
| 29 | NIS_DOMAIN_NAME | Yes | Yes |
| 30 | NISP_DOMAIN_NAME | Yes | Yes |
| 31 | SNTP_SERVERS | Yes | Yes |
| 32 | INFORMATION_REFRESH_TIME | Required for | Yes |
| | | Information- | |
| | | request | |
| 33 | BCMCS_SERVER_D | Yes | Yes |
| 34 | BCMCS_SERVER_A | Yes | Yes |
| 36 | GEOCONF_CIVIC | Yes | Yes |
| 37 | REMOTE_ID | No | Yes |
| 38 | SUBSCRIBER_ID | No | Yes |
| 39 | CLIENT_FQDN | Yes | Yes |
| 40 | PANA_AGENT | Yes | Yes |
| 41 | NEW_POSIX_TIMEZONE | Yes | Yes |
| 42 | NEW_TZDB_TIMEZONE | Yes | Yes |
| 43 | ERO | No | Yes |
| 44 | LQ_QUERY | No | Yes |
| 45 | CLIENT_DATA | No | Yes |
| 46 | CLT_TIME | No | Yes |
| 47 | LQ_RELAY_DATA | No | Yes |
| 48 | LQ_CLIENT_LINK | No | Yes |
| 49 | MIP6_HNIDF | Yes | Yes |
| 50 | MIP6_VDINF | Yes | Yes |
| 51 | V6_LOST | Yes | Yes |
| 52 | CAPWAP_AC_V6 | Yes | Yes |
| 53 | RELAY_ID | No | Yes |
| 54 | IPv6_Address-MoS | Yes | Yes |
| 55 | IPv6_FQDN-MoS | Yes | Yes |
| 56 | NTP_SERVER | Yes | Yes |
| 57 | V6_ACCESS_DOMAIN | Yes | Yes |
| 58 | SIP_UA_CS_LIST | Yes | Yes |
| 59 | OPT_BOOTFILE_URL | Yes | Yes |
| 60 | OPT_BOOTFILE_PARAM | Yes | Yes |
| 61 | CLIENT_ARCH_TYPE | No | Yes |
| 62 | NII | Yes | Yes |
| 63 | GEOLOCATION | Yes | Yes |
| 64 | AFTR_NAME | Yes | Yes |
| 65 | ERP_LOCAL_DOMAIN_NAME | Yes | Yes |
| 66 | RSOO | No | Yes |
| 67 | PD_EXCLUDE | Yes | Yes |
| 68 | VSS | No | Yes |
| 69 | MIP6_IDINF | Yes | Yes |
| 70 | MIP6_UDINF | Yes | Yes |
| 71 | MIP6_HNP | Yes | Yes |
| 72 | MIP6_HAA | Yes | Yes |
| 73 | MIP6_HAF | Yes | Yes |
| 74 | RDNSS_SELECTION | Yes | No |
| 75 | KRB_PRINCIPAL_NAME | Yes | Yes |
| 76 | KRB_REALM_NAME | Yes | Yes |
| 77 | KRB_DEFAULT_REALM_NAME | Yes | Yes |
| 78 | KRB_KDC | Yes | Yes |
| 79 | CLIENT_LINKLAYER_ADDR | No | Yes |
| 80 | LINK_ADDRESS | No | Yes |
| 81 | RADIUS | No | Yes |
| 82 | SOL_MAX_RT | Required for | Yes |
| | | Solicit | |
| 83 | INF_MAX_RT | Required for | Yes |
| | | Information- | |
| | | request | |
| 84 | ADDRSEL | Yes | Yes |
| 85 | ADDRSEL_TABLE | Yes | Yes |
| 41 | NEW_POSIX_TIMEZONE | Yes | Yes |
| 42 | NEW_TZDB_TIMEZONE | Yes | Yes |
| 43 | ERO | No | Yes |
| 44 | LQ_QUERY | No | Yes |
| 45 | CLIENT_DATA | No | Yes |
| 46 | CLT_TIME | No | Yes |
| 47 | LQ_RELAY_DATA | No | Yes |
| 48 | LQ_CLIENT_LINK | No | Yes |
| 49 | MIP6_HNIDF | Yes | Yes |
| 50 | MIP6_VDINF | Yes | Yes |
| 51 | V6_LOST | Yes | Yes |
| 52 | CAPWAP_AC_V6 | Yes | Yes |
| 53 | RELAY_ID | No | Yes |
| 54 | IPv6_Address-MoS | Yes | Yes |
| 55 | IPv6_FQDN-MoS | Yes | Yes |
| 56 | NTP_SERVER | Yes | Yes |
| 57 | V6_ACCESS_DOMAIN | Yes | Yes |
| 58 | SIP_UA_CS_LIST | Yes | Yes |
| 59 | OPT_BOOTFILE_URL | Yes | Yes |
| 60 | OPT_BOOTFILE_PARAM | Yes | Yes |
| 61 | CLIENT_ARCH_TYPE | No | Yes |
| 62 | NII | Yes | Yes |
| 63 | GEOLOCATION | Yes | Yes |
| 64 | AFTR_NAME | Yes | Yes |
| 65 | ERP_LOCAL_DOMAIN_NAME | Yes | Yes |
| 66 | RSOO | No | Yes |
| 67 | PD_EXCLUDE | Yes | Yes |
| 68 | VSS | No | Yes |
| 69 | MIP6_IDINF | Yes | Yes |
| 70 | MIP6_UDINF | Yes | Yes |
| 71 | MIP6_HNP | Yes | Yes |
| 72 | MIP6_HAA | Yes | Yes |
| 73 | MIP6_HAF | Yes | Yes |
| 74 | RDNSS_SELECTION | Yes | No |
| 75 | KRB_PRINCIPAL_NAME | Yes | Yes |
| 76 | KRB_REALM_NAME | Yes | Yes |
| 77 | KRB_DEFAULT_REALM_NAME | Yes | Yes |
| 78 | KRB_KDC | Yes | Yes |
| 79 | CLIENT_LINKLAYER_ADDR | No | Yes |
| 80 | LINK_ADDRESS | No | Yes |
| 81 | RADIUS | No | Yes |
| 82 | SOL_MAX_RT | Required for | Yes |
| | | Solicit | |
| 83 | INF_MAX_RT | Required for | Yes |
| | | Information- | |
| | | request | |
| 84 | ADDRSEL | Yes | Yes |
| 85 | ADDRSEL_TABLE | Yes | Yes |
| 86 | V6_PCP_SERVER | Yes | No |
| 87 | DHCPV4_MSG | No | Yes |
| 88 | DHCP4_O_DHCP6_SERVER | Yes | Yes |
| 89 | S46_RULE | No | No (3) |
| 90 | S46_BR | No | No |
| 91 | S46_DMR | No | Yes |
| 92 | S46_V4V6BIND | No | Yes |
| 93 | S46_PORTPARAMS | No | Yes |
| 94 | S46_CONT_MAPE | Yes | No |
| 95 | S46_CONT_MAPT | Yes | Yes |
| 96 | S46_CONT_LW | Yes | Yes |
| 97 | 4RD | Yes | Yes |
| 98 | 4RD_MAP_RULE | Yes | Yes |
| 99 | 4RD_NON_MAP_RULE | Yes | Yes |
| 100 | LQ_BASE_TIME | No | Yes |
| 101 | LQ_START_TIME | No | Yes |
| 102 | LQ_END_TIME | No | Yes |
| 103 | DHCP Captive-Portal | Yes | Yes |
| 104 | MPL_PARAMETERS | Yes | No |
| 105 | ANI_ATT | No | Yes |
| 106 | ANI_NETWORK_NAME | No | Yes |
| 107 | ANI_AP_NAME | No | Yes |
| 108 | ANI_AP_BSSID | No | Yes |
| 109 | ANI_OPERATOR_ID | No | Yes |
| 110 | ANI_OPERATOR_REALM | No | Yes |
| 111 | S46_PRIORITY | Yes | Yes |
| 112 | MUD_URL_V6 | No | Yes |
| 113 | V6_PREFIX64 | Yes | No |
| 114 | F_BINDING_STATUS | No | Yes |
| 115 | F_CONNECT_FLAGS | No | Yes |
| 116 | F_DNS_REMOVAL_INFO | No | Yes |
| 117 | F_DNS_HOST_NAME | No | Yes |
| 118 | F_DNS_ZONE_NAME | No | Yes |
| 119 | F_DNS_FLAGS | No | Yes |
| 120 | F_EXPIRATION_TIME | No | Yes |
| 121 | F_MAX_UNACKED_BNDUPD | No | Yes |
| 122 | F_MCLT | No | Yes |
| 123 | F_PARTNER_LIFETIME | No | Yes |
| 124 | F_PARTNER_LIFETIME_SENT | No | Yes |
| 125 | F_PARTNER_DOWN_TIME | No | Yes |
| 126 | F_PARTNER_RAW_CLT_TIME | No | Yes |
| 127 | F_PROTOCOL_VERSION | No | Yes |
| 128 | F_KEEPALIVE_TIME | No | Yes |
| 129 | F_RECONFIGURE_DATA | No | Yes |
| 130 | F_RELATIONSHIP_NAME | No | Yes |
| 131 | F_SERVER_FLAGS | No | Yes |
| 132 | F_SERVER_STATE | No | Yes |
| 133 | F_START_TIME_OF_STATE | No | Yes |
| 86 | V6_PCP_SERVER | Yes | No |
| 87 | DHCPV4_MSG | No | Yes |
| 88 | DHCP4_O_DHCP6_SERVER | Yes | Yes |
| 89 | S46_RULE | No | No (3) |
| 90 | S46_BR | No | No |
| 91 | S46_DMR | No | Yes |
| 92 | S46_V4V6BIND | No | Yes |
| 93 | S46_PORTPARAMS | No | Yes |
| 94 | S46_CONT_MAPE | Yes | No |
| 95 | S46_CONT_MAPT | Yes | Yes |
| 96 | S46_CONT_LW | Yes | Yes |
| 97 | 4RD | Yes | Yes |
| 98 | 4RD_MAP_RULE | Yes | Yes |
| 99 | 4RD_NON_MAP_RULE | Yes | Yes |
| 100 | LQ_BASE_TIME | No | Yes |
| 101 | LQ_START_TIME | No | Yes |
| 102 | LQ_END_TIME | No | Yes |
| 103 | DHCP Captive-Portal | Yes | Yes |
| 104 | MPL_PARAMETERS | Yes | No |
| 105 | ANI_ATT | No | Yes |
| 106 | ANI_NETWORK_NAME | No | Yes |
| 107 | ANI_AP_NAME | No | Yes |
| 108 | ANI_AP_BSSID | No | Yes |
| 109 | ANI_OPERATOR_ID | No | Yes |
| 110 | ANI_OPERATOR_REALM | No | Yes |
| 111 | S46_PRIORITY | Yes | Yes |
| 112 | MUD_URL_V6 | No | Yes |
| 113 | V6_PREFIX64 | Yes | No |
| 114 | F_BINDING_STATUS | No | Yes |
| 115 | F_CONNECT_FLAGS | No | Yes |
| 116 | F_DNS_REMOVAL_INFO | No | Yes |
| 117 | F_DNS_HOST_NAME | No | Yes |
| 118 | F_DNS_ZONE_NAME | No | Yes |
| 119 | F_DNS_FLAGS | No | Yes |
| 120 | F_EXPIRATION_TIME | No | Yes |
| 121 | F_MAX_UNACKED_BNDUPD | No | Yes |
| 122 | F_MCLT | No | Yes |
| 123 | F_PARTNER_LIFETIME | No | Yes |
| 124 | F_PARTNER_LIFETIME_SENT | No | Yes |
| 125 | F_PARTNER_DOWN_TIME | No | Yes |
| 126 | F_PARTNER_RAW_CLT_TIME | No | Yes |
| 127 | F_PROTOCOL_VERSION | No | Yes |
| 128 | F_KEEPALIVE_TIME | No | Yes |
| 129 | F_RECONFIGURE_DATA | No | Yes |
| 130 | F_RELATIONSHIP_NAME | No | Yes |
| 131 | F_SERVER_FLAGS | No | Yes |
| 132 | F_SERVER_STATE | No | Yes |
| 133 | F_START_TIME_OF_STATE | No | Yes |
| 134 | F_STATE_EXPIRATION_TIME | No | Yes |
| 135 | RELAY_PORT | No | Yes |
| 143 | IPv6_Address-ANDSF | Yes | Yes |
+---------+--------------------------+------------------+-----------+
| 134 | F_STATE_EXPIRATION_TIME | No | Yes |
| 135 | RELAY_PORT | No | Yes |
| 143 | IPv6_Address-ANDSF | Yes | Yes |
+---------+--------------------------+------------------+-----------+
Table 4: Updated Options
表4：更新的选项
Notes for Table 4:
表4的注释：
(1) In the "Client ORO" column, a "Yes" for an option means that the client includes this option code in the Option Request option (see Section 21.7) if it desires that configuration information, and a "No" means that the option MUST NOT be included (and servers SHOULD silently ignore that option code if it appears in a client's Option Request option).
(1) 在“客户机ORO”列中，选项的“是”表示客户机需要该配置信息时在选项请求选项中包含该选项代码（参见第21.7节），而“否”表示不得包含该选项（如果该选项代码出现在客户机的选项请求选项中，服务器应默默忽略该选项代码）.
(2) For each Enterprise Number, there MUST only be a single instance.
(2) 对于每个企业编号，必须只有一个实例。
(3) See [RFC7598] for details.
(3) 详见[RFC7598]。
IANA has corrected the range of possible status codes in the "Status Codes" table at <https://www.iana.org/assignments/dhcpv6-parameters> by replacing 23-255 (as Unassigned) with 23-65535 (the codes are 16-bit unsigned integers).
IANA已在“状态代码”表中更正了可能的状态代码范围<https://www.iana.org/assignments/dhcpv6-parameters>将23-255（未赋值）替换为23-65535（代码为16位无符号整数）。
IANA has updated the All_DHCP_Relay_Agents_and_Servers (ff02::1:2) and All_DHCP_Servers (ff05::1:3) table entries in the "IPv6 Multicast Address Space Registry" at <https://www.iana.org/assignments/ ipv6-multicast-addresses> to reference this document instead of [RFC3315].
IANA已更新“IPv6多播地址空间注册表”中的所有\u DHCP\u中继\u代理\u和\u服务器（ff02:：1:2）以及所有\u DHCP\u服务器（ff05:：1:3）表项<https://www.iana.org/assignments/ ipv6多播地址>以引用此文档而不是[RFC3315]。
IANA has added an "Obsolete" annotation in the "DHCPv6 Delayed Authentication" entry in the "Authentication Suboption (value 8) - Protocol identifier values" registry at <https://www.iana.org/assignments/bootp-dhcp-parameters> and has added an "Obsolete" annotation in the "Delayed Authentication" entry in the "Protocol Name Space Values" registry at <https://www.iana.org/assignments/auth-namespaces>. IANA has also updated these pages to reference this document instead of [RFC3315].
IANA在“身份验证子选项（值8）-协议标识符值”注册表中的“DHCPv6延迟身份验证”条目中添加了一个“过时”注释<https://www.iana.org/assignments/bootp-dhcp-parameters>并在“协议名称空间值”的“延迟身份验证”条目中添加了“过时”注释注册处<https://www.iana.org/assignments/auth-namespaces>. IANA还更新了这些页面，以引用本文件，而不是[RFC3315]。
IANA has added a reference to this document for the RDM value of 0 to the "RDM Name Space Values" registry at <https://www.iana.org/assignments/auth-namespaces>.
IANA已将RDM值为0的本文档参考添加到位于的“RDM名称空间值”注册表中<https://www.iana.org/assignments/auth-namespaces>.
IANA has updated the "Service Name and Transport Protocol Port Number Registry" at <https://www.iana.org/assignments/ service-names-port-numbers> as follows:
IANA已在更新“服务名称和传输协议端口号注册表”<https://www.iana.org/assignments/ 服务名称端口号>如下所示：
546/udp This document 547/udp This document 547/tcp [RFC5460] 647/tcp [RFC8156]
546/udp本文件547/udp本文件547/tcp[RFC5460]647/tcp[RFC8156]
This specification is mostly a corrected and cleaned-up version of the original specification -- [RFC3315] -- along with numerous additions from later RFCs. However, there are a small number of mechanisms that were not widely deployed, were underspecified, or had other operational issues. Those mechanisms are now considered deprecated. Legacy implementations MAY support them, but implementations conformant to this document MUST NOT rely on them.
本规范主要是原始规范[RFC3315]的修正版和清理版，以及后来的RFC中的大量新增内容。然而，有少数机制没有得到广泛部署，没有得到明确规定，或者存在其他操作问题。这些机制现在被认为是不推荐的。遗留实现可能支持它们，但符合本文档的实现不得依赖它们。
The following mechanisms are now obsolete:
以下机制现已过时：
Delayed authentication. This mechanism was underspecified and presented a significant operational burden. As a result, after 10 years its adoption was extremely limited at best.
延迟认证。这一机制没有明确规定，造成了巨大的操作负担。因此，在10年之后，它的采用充其量也极为有限。
Lifetime hints sent by a client. Clients used to be allowed to send lifetime values as hints. This mechanism was not widely implemented, and there were known misimplementations that sent the remaining lifetimes rather than total desired lifetimes. That in turn was sometimes misunderstood by servers as a request for ever-decreasing lease lifetimes, which caused issues when values started approaching zero. Clients now SHOULD set lifetimes to 0 in IA Address and IA Prefix options, and servers MUST ignore any requested lifetime value.
客户端发送的生存期提示。过去，客户端被允许将生存期值作为提示发送。这种机制没有得到广泛的实现，并且存在已知的错误实现，它们发送的是剩余的生命周期，而不是总的期望生命周期。这反过来又被服务器误解为要求不断缩短租赁寿命，这在值开始接近零时会导致问题。客户端现在应该在IA地址和IA前缀选项中将生存时间设置为0，服务器必须忽略任何请求的生存时间值。
T1/T2 hints sent by a client. These had issues similar to those for the lifetime hints. Clients now SHOULD set the T1/T2 values to 0 in IA_NA and IA_PD options, and servers MUST ignore any T1/T2 values supplied by a client.
客户端发送的T1/T2提示。这些问题与生命周期提示类似。客户端现在应该在IA_NA和IA_PD选项中将T1/T2值设置为0，服务器必须忽略客户端提供的任何T1/T2值。
[RFC768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, <https://www.rfc-editor.org/info/rfc768>.
[RFC768]Postel，J.，“用户数据报协议”，STD 6，RFC 768，DOI 10.17487/RFC0768，1980年8月<https://www.rfc-editor.org/info/rfc768>.
[RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, DOI 10.17487/RFC1035, November 1987, <https://www.rfc-editor.org/info/rfc1035>.
[RFC1035]Mockapetris，P.，“域名-实现和规范”，STD 13，RFC 1035，DOI 10.17487/RFC1035，1987年11月<https://www.rfc-editor.org/info/rfc1035>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<https://www.rfc-editor.org/info/rfc2119>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 4291, DOI 10.17487/RFC4291, February 2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4291]Hinden，R.和S.Deering，“IP版本6寻址体系结构”，RFC 4291，DOI 10.17487/RFC42912006年2月<https://www.rfc-editor.org/info/rfc4291>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, DOI 10.17487/RFC4861, September 2007, <https://www.rfc-editor.org/info/rfc4861>.
[RFC4861]Narten，T.，Nordmark，E.，Simpson，W.，和H.Soliman，“IP版本6（IPv6）的邻居发现”，RFC 4861，DOI 10.17487/RFC48612007年9月<https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, DOI 10.17487/RFC4862, September 2007, <https://www.rfc-editor.org/info/rfc4862>.
[RFC4862]Thomson，S.，Narten，T.和T.Jinmei，“IPv6无状态地址自动配置”，RFC 4862，DOI 10.17487/RFC4862，2007年9月<https://www.rfc-editor.org/info/rfc4862>.
[RFC6221] Miles, D., Ed., Ooghe, S., Dec, W., Krishnan, S., and A. Kavanagh, "Lightweight DHCPv6 Relay Agent", RFC 6221, DOI 10.17487/RFC6221, May 2011, <https://www.rfc-editor.org/info/rfc6221>.
[RFC6221]Miles，D.，Ed.，Ooghe，S.，Dec，W.，Krishnan，S.，和A.Kavanagh，“轻型DHCPv6中继代理”，RFC 6221DOI 10.17487/RFC6221，2011年5月<https://www.rfc-editor.org/info/rfc6221>.
[RFC6355] Narten, T. and J. Johnson, "Definition of the UUID-Based DHCPv6 Unique Identifier (DUID-UUID)", RFC 6355, DOI 10.17487/RFC6355, August 2011, <https://www.rfc-editor.org/info/rfc6355>.
[RFC6355]Narten，T.和J.Johnson，“基于UUID的DHCPv6唯一标识符（DUID-UUID）的定义”，RFC 6355，DOI 10.17487/RFC6355，2011年8月<https://www.rfc-editor.org/info/rfc6355>.
[RFC7227] Hankins, D., Mrugalski, T., Siodelski, M., Jiang, S., and S. Krishnan, "Guidelines for Creating New DHCPv6 Options", BCP 187, RFC 7227, DOI 10.17487/RFC7227, May 2014, <https://www.rfc-editor.org/info/rfc7227>.
[RFC7227]Hankins，D.，Mrugalski，T.，Siodelski，M.，Jiang，S.，和S.Krishnan，“创建新DHCPv6选项的指南”，BCP 187，RFC 7227，DOI 10.17487/RFC7227，2014年5月<https://www.rfc-editor.org/info/rfc7227>.
[RFC7283] Cui, Y., Sun, Q., and T. Lemon, "Handling Unknown DHCPv6 Messages", RFC 7283, DOI 10.17487/RFC7283, July 2014, <https://www.rfc-editor.org/info/rfc7283>.
[RFC7283]Cui，Y.，Sun，Q.，和T.Lemon，“处理未知DHCPv6消息”，RFC 7283，DOI 10.17487/RFC7283，2014年7月<https://www.rfc-editor.org/info/rfc7283>.
[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, March 2017, <https://www.rfc-editor.org/info/rfc8085>.
[RFC8085]Eggert，L.，Fairhurst，G.和G.Shepherd，“UDP使用指南”，BCP 145，RFC 8085，DOI 10.17487/RFC8085，2017年3月<https://www.rfc-editor.org/info/rfc8085>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8174]Leiba，B.，“RFC 2119关键词中大写与小写的歧义”，BCP 14，RFC 8174，DOI 10.17487/RFC8174，2017年5月<https://www.rfc-editor.org/info/rfc8174>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, <https://www.rfc-editor.org/info/rfc8200>.
[RFC8200]Deering，S.和R.Hinden，“互联网协议，第6版（IPv6）规范”，STD 86，RFC 8200，DOI 10.17487/RFC8200，2017年7月<https://www.rfc-editor.org/info/rfc8200>.
[RFC8213] Volz, B. and Y. Pal, "Security of Messages Exchanged between Servers and Relay Agents", RFC 8213, DOI 10.17487/RFC8213, August 2017, <https://www.rfc-editor.org/info/rfc8213>.
[RFC8213]Volz，B.和Y.Pal，“服务器和中继代理之间交换的消息的安全性”，RFC 8213，DOI 10.17487/RFC8213，2017年8月<https://www.rfc-editor.org/info/rfc8213>.
[IANA-HARDWARE-TYPES] IANA, "Hardware Types", <https://www.iana.org/assignments/arp-parameters>.
[IANA-HARDWARE-TYPES]IANA，“硬件类型”<https://www.iana.org/assignments/arp-parameters>.
[IANA-PEN] IANA, "Private Enterprise Numbers", <https://www.iana.org/assignments/enterprise-numbers>.
[IANA-PEN]IANA，“私营企业编号”<https://www.iana.org/assignments/enterprise-numbers>.
[IANA-RESERVED-IID] IANA, "Reserved IPv6 Interface Identifiers", <https://www.iana.org/assignments/ipv6-interface-ids>.
[IANA-REFERED-IID]IANA，“保留IPv6接口标识符”<https://www.iana.org/assignments/ipv6-interface-ids>.
[IEEE-802.1x] IEEE, "IEEE Standard for Local and metropolitan area networks--Port-Based Network Access Control", IEEE 802.1X-2010, DOI 10.1109/IEEESTD.2010.5409813, <https://ieeexplore.ieee.org/servlet/ opac?punumber=5409757>.
[IEEE-802.1x]IEEE，“局域网和城域网的IEEE标准——基于端口的网络访问控制”，IEEE 802.1x-2010，DOI 10.1109/IEEESTD.2010.5409813<https://ieeexplore.ieee.org/servlet/ opac？punumber=5409757>。
[RFC826] Plummer, D., "An Ethernet Address Resolution Protocol: Or Converting Network Protocol Addresses to 48.bit Ethernet Address for Transmission on Ethernet Hardware", STD 37, RFC 826, DOI 10.17487/RFC0826, November 1982, <https://www.rfc-editor.org/info/rfc826>.
[RFC826]Plummer，D.“以太网地址解析协议：或将网络协议地址转换为48位以太网地址以便在以太网硬件上传输”，STD 37，RFC 826，DOI 10.17487/RFC0826，1982年11月<https://www.rfc-editor.org/info/rfc826>.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, DOI 10.17487/RFC2131, March 1997, <https://www.rfc-editor.org/info/rfc2131>.
[RFC2131]Droms，R.，“动态主机配置协议”，RFC 2131，DOI 10.17487/RFC2131，1997年3月<https://www.rfc-editor.org/info/rfc2131>.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC 2132, DOI 10.17487/RFC2132, March 1997, <https://www.rfc-editor.org/info/rfc2132>.
[RFC2132]Alexander，S.和R.Droms，“DHCP选项和BOOTP供应商扩展”，RFC 2132，DOI 10.17487/RFC2132，1997年3月<https://www.rfc-editor.org/info/rfc2132>.
[RFC2464] Crawford, M., "Transmission of IPv6 Packets over Ethernet Networks", RFC 2464, DOI 10.17487/RFC2464, December 1998, <https://www.rfc-editor.org/info/rfc2464>.
[RFC2464]克劳福德，M.，“通过以太网传输IPv6数据包”，RFC 2464，DOI 10.17487/RFC2464，1998年12月<https://www.rfc-editor.org/info/rfc2464>.
[RFC3162] Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6", RFC 3162, DOI 10.17487/RFC3162, August 2001, <https://www.rfc-editor.org/info/rfc3162>.
[RFC3162]Aboba，B.，Zorn，G.和D.Mitton，“RADIUS和IPv6”，RFC 3162，DOI 10.17487/RFC3162，2001年8月<https://www.rfc-editor.org/info/rfc3162>.
[RFC3290] Bernet, Y., Blake, S., Grossman, D., and A. Smith, "An Informal Management Model for Diffserv Routers", RFC 3290, DOI 10.17487/RFC3290, May 2002, <https://www.rfc-editor.org/info/rfc3290>.
[RFC3290]Bernet，Y.，Blake，S.，Grossman，D.，和A.Smith，“区分服务路由器的非正式管理模型”，RFC 3290，DOI 10.17487/RFC3290，2002年5月<https://www.rfc-editor.org/info/rfc3290>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July 2003, <https://www.rfc-editor.org/info/rfc3315>.
[RFC3315]Droms，R.，Ed.，Bound，J.，Volz，B.，Lemon，T.，Perkins，C.，和M.Carney，“IPv6的动态主机配置协议（DHCPv6）”，RFC 3315，DOI 10.17487/RFC3315，2003年7月<https://www.rfc-editor.org/info/rfc3315>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November 2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC3629]Yergeau，F.，“UTF-8，ISO 10646的转换格式”，STD 63，RFC 3629，DOI 10.17487/RFC3629，2003年11月<https://www.rfc-editor.org/info/rfc3629>.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, DOI 10.17487/RFC3633, December 2003, <https://www.rfc-editor.org/info/rfc3633>.
[RFC3633]Troan，O.和R.Droms，“动态主机配置协议（DHCP）版本6的IPv6前缀选项”，RFC 3633，DOI 10.17487/RFC3633，2003年12月<https://www.rfc-editor.org/info/rfc3633>.
[RFC3646] Droms, R., Ed., "DNS Configuration options for Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3646, DOI 10.17487/RFC3646, December 2003, <https://www.rfc-editor.org/info/rfc3646>.
[RFC3646]Droms，R.，Ed.“IPv6动态主机配置协议（DHCPv6）的DNS配置选项”，RFC 3646，DOI 10.17487/RFC3646，2003年12月<https://www.rfc-editor.org/info/rfc3646>.
[RFC3736] Droms, R., "Stateless Dynamic Host Configuration Protocol (DHCP) Service for IPv6", RFC 3736, DOI 10.17487/RFC3736, April 2004, <https://www.rfc-editor.org/info/rfc3736>.
[RFC3736]Droms，R.，“IPv6的无状态动态主机配置协议（DHCP）服务”，RFC 3736，DOI 10.17487/RFC3736，2004年4月<https://www.rfc-editor.org/info/rfc3736>.
[RFC3769] Miyakawa, S. and R. Droms, "Requirements for IPv6 Prefix Delegation", RFC 3769, DOI 10.17487/RFC3769, June 2004, <https://www.rfc-editor.org/info/rfc3769>.
[RFC3769]Miyakawa，S.和R.Droms，“IPv6前缀委派的要求”，RFC 3769，DOI 10.17487/RFC3769，2004年6月<https://www.rfc-editor.org/info/rfc3769>.
[RFC4193] Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast Addresses", RFC 4193, DOI 10.17487/RFC4193, October 2005, <https://www.rfc-editor.org/info/rfc4193>.
[RFC4193]Hinden，R.和B.Haberman，“唯一本地IPv6单播地址”，RFC 4193，DOI 10.17487/RFC4193，2005年10月<https://www.rfc-editor.org/info/rfc4193>.
[RFC4242] Venaas, S., Chown, T., and B. Volz, "Information Refresh Time Option for Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 4242, DOI 10.17487/RFC4242, November 2005, <https://www.rfc-editor.org/info/rfc4242>.
[RFC4242]Venaas，S.，Chown，T.，和B.Volz，“IPv6动态主机配置协议（DHCPv6）的信息刷新时间选项”，RFC 4242，DOI 10.17487/RFC4242，2005年11月<https://www.rfc-editor.org/info/rfc4242>.
[RFC4477] Chown, T., Venaas, S., and C. Strauf, "Dynamic Host Configuration Protocol (DHCP): IPv4 and IPv6 Dual-Stack Issues", RFC 4477, DOI 10.17487/RFC4477, May 2006, <https://www.rfc-editor.org/info/rfc4477>.
[RFC4477]Chown，T.，Venaas，S.，和C.Strauf，“动态主机配置协议（DHCP）：IPv4和IPv6双栈问题”，RFC 4477，DOI 10.17487/RFC4477，2006年5月<https://www.rfc-editor.org/info/rfc4477>.
[RFC4704] Volz, B., "The Dynamic Host Configuration Protocol for IPv6 (DHCPv6) Client Fully Qualified Domain Name (FQDN) Option", RFC 4704, DOI 10.17487/RFC4704, October 2006, <https://www.rfc-editor.org/info/rfc4704>.
[RFC4704]Volz，B.，“IPv6（DHCPv6）客户端完全限定域名（FQDN）选项的动态主机配置协议”，RFC 4704，DOI 10.17487/RFC4704，2006年10月<https://www.rfc-editor.org/info/rfc4704>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007, <https://www.rfc-editor.org/info/rfc4941>.
[RFC4941]Narten，T.，Draves，R.，和S.Krishnan，“IPv6中无状态地址自动配置的隐私扩展”，RFC 4941，DOI 10.17487/RFC49411907年9月<https://www.rfc-editor.org/info/rfc4941>.
[RFC4943] Roy, S., Durand, A., and J. Paugh, "IPv6 Neighbor Discovery On-Link Assumption Considered Harmful", RFC 4943, DOI 10.17487/RFC4943, September 2007, <https://www.rfc-editor.org/info/rfc4943>.
[RFC4943]Roy，S.，Durand，A.，和J.Paugh，“基于链路假设的IPv6邻居发现被认为是有害的”，RFC 4943，DOI 10.17487/RFC4943，2007年9月<https://www.rfc-editor.org/info/rfc4943>.
[RFC4994] Zeng, S., Volz, B., Kinnear, K., and J. Brzozowski, "DHCPv6 Relay Agent Echo Request Option", RFC 4994, DOI 10.17487/RFC4994, September 2007, <https://www.rfc-editor.org/info/rfc4994>.
[RFC4994]Zeng，S.，Volz，B.，Kinnear，K.，和J.Brzowski，“DHCPv6中继代理回送请求选项”，RFC 4994，DOI 10.17487/RFC49942007年9月<https://www.rfc-editor.org/info/rfc4994>.
[RFC5007] Brzozowski, J., Kinnear, K., Volz, B., and S. Zeng, "DHCPv6 Leasequery", RFC 5007, DOI 10.17487/RFC5007, September 2007, <https://www.rfc-editor.org/info/rfc5007>.
[RFC5007]Brzowski，J.，Kinnear，K.，Volz，B.，和S.Zeng，“DHCPv6租赁”，RFC 5007，DOI 10.17487/RFC5007，2007年9月<https://www.rfc-editor.org/info/rfc5007>.
[RFC5453] Krishnan, S., "Reserved IPv6 Interface Identifiers", RFC 5453, DOI 10.17487/RFC5453, February 2009, <https://www.rfc-editor.org/info/rfc5453>.
[RFC5453]Krishnan，S.，“保留IPv6接口标识符”，RFC 5453，DOI 10.17487/RFC5453，2009年2月<https://www.rfc-editor.org/info/rfc5453>.
[RFC5460] Stapp, M., "DHCPv6 Bulk Leasequery", RFC 5460, DOI 10.17487/RFC5460, February 2009, <https://www.rfc-editor.org/info/rfc5460>.
[RFC5460]Stapp，M.，“DHCPv6散装租赁”，RFC 5460，DOI 10.17487/RFC5460，2009年2月<https://www.rfc-editor.org/info/rfc5460>.
[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, <https://www.rfc-editor.org/info/rfc5905>.
[RFC5905]Mills，D.，Martin，J.，Ed.，Burbank，J.，和W.Kasch，“网络时间协议版本4：协议和算法规范”，RFC 5905，DOI 10.17487/RFC59052010年6月<https://www.rfc-editor.org/info/rfc5905>.
[RFC5908] Gayraud, R. and B. Lourdelet, "Network Time Protocol (NTP) Server Option for DHCPv6", RFC 5908, DOI 10.17487/RFC5908, June 2010, <https://www.rfc-editor.org/info/rfc5908>.
[RFC5908]Gayraud，R.和B.Lourdelet，“DHCPv6的网络时间协议（NTP）服务器选项”，RFC 5908，DOI 10.17487/RFC5908，2010年6月<https://www.rfc-editor.org/info/rfc5908>.
[RFC6422] Lemon, T. and Q. Wu, "Relay-Supplied DHCP Options", RFC 6422, DOI 10.17487/RFC6422, December 2011, <https://www.rfc-editor.org/info/rfc6422>.
[RFC6422]Lemon，T.和Q.Wu，“继电器提供的DHCP选项”，RFC 6422，DOI 10.17487/RFC6422，2011年12月<https://www.rfc-editor.org/info/rfc6422>.
[RFC6603] Korhonen, J., Ed., Savolainen, T., Krishnan, S., and O. Troan, "Prefix Exclude Option for DHCPv6-based Prefix Delegation", RFC 6603, DOI 10.17487/RFC6603, May 2012, <https://www.rfc-editor.org/info/rfc6603>.
[RFC6603]Korhonen，J.，Ed.，Savolainen，T.，Krishnan，S.，和O.Troan，“基于DHCPv6的前缀委托的前缀排除选项”，RFC 6603，DOI 10.17487/RFC6603，2012年5月<https://www.rfc-editor.org/info/rfc6603>.
[RFC6724] Thaler, D., Ed., Draves, R., Matsumoto, A., and T. Chown, "Default Address Selection for Internet Protocol Version 6 (IPv6)", RFC 6724, DOI 10.17487/RFC6724, September 2012, <https://www.rfc-editor.org/info/rfc6724>.
[RFC6724]Thaler，D.，Ed.，Draves，R.，Matsumoto，A.，和T.Chown，“互联网协议版本6（IPv6）的默认地址选择”，RFC 6724，DOI 10.17487/RFC67242012年9月<https://www.rfc-editor.org/info/rfc6724>.
[RFC6879] Jiang, S., Liu, B., and B. Carpenter, "IPv6 Enterprise Network Renumbering Scenarios, Considerations, and Methods", RFC 6879, DOI 10.17487/RFC6879, February 2013, <https://www.rfc-editor.org/info/rfc6879>.
[RFC6879]Jiang，S.，Liu，B.和B.Carpenter，“IPv6企业网络重新编号方案、注意事项和方法”，RFC 6879，DOI 10.17487/RFC6879，2013年2月<https://www.rfc-editor.org/info/rfc6879>.
[RFC6939] Halwasia, G., Bhandari, S., and W. Dec, "Client Link-Layer Address Option in DHCPv6", RFC 6939, DOI 10.17487/RFC6939, May 2013, <https://www.rfc-editor.org/info/rfc6939>.
[RFC6939]Halwasia，G.，Bhandari，S.，和W.Dec，“DHCPv6中的客户链路层地址选项”，RFC 6939，DOI 10.17487/RFC6939，2013年5月<https://www.rfc-editor.org/info/rfc6939>.
[RFC7083] Droms, R., "Modification to Default Values of SOL_MAX_RT and INF_MAX_RT", RFC 7083, DOI 10.17487/RFC7083, November 2013, <https://www.rfc-editor.org/info/rfc7083>.
[RFC7083]Droms，R.，“修改SOL_MAX_RT和INF_MAX_RT的默认值”，RFC 7083，DOI 10.17487/RFC7083，2013年11月<https://www.rfc-editor.org/info/rfc7083>.
[RFC7084] Singh, H., Beebee, W., Donley, C., and B. Stark, "Basic Requirements for IPv6 Customer Edge Routers", RFC 7084, DOI 10.17487/RFC7084, November 2013, <https://www.rfc-editor.org/info/rfc7084>.
[RFC7084]Singh，H.，Beebee，W.，Donley，C.，和B.Stark，“IPv6客户边缘路由器的基本要求”，RFC 7084，DOI 10.17487/RFC7084，2013年11月<https://www.rfc-editor.org/info/rfc7084>.
[RFC7136] Carpenter, B. and S. Jiang, "Significance of IPv6 Interface Identifiers", RFC 7136, DOI 10.17487/RFC7136, February 2014, <https://www.rfc-editor.org/info/rfc7136>.
[RFC7136]Carpenter，B.和S.Jiang，“IPv6接口标识符的重要性”，RFC 7136，DOI 10.17487/RFC7136，2014年2月<https://www.rfc-editor.org/info/rfc7136>.
[RFC7341] Sun, Q., Cui, Y., Siodelski, M., Krishnan, S., and I. Farrer, "DHCPv4-over-DHCPv6 (DHCP 4o6) Transport", RFC 7341, DOI 10.17487/RFC7341, August 2014, <https://www.rfc-editor.org/info/rfc7341>.
[RFC7341]Sun，Q.，Cui，Y.，Siodelski，M.，Krishnan，S.，和I.Farrer，“DHCPv4-over-DHCPv6（DHCP 4o6）传输”，RFC 7341，DOI 10.17487/RFC73412014年8月<https://www.rfc-editor.org/info/rfc7341>.
[RFC7368] Chown, T., Ed., Arkko, J., Brandt, A., Troan, O., and J. Weil, "IPv6 Home Networking Architecture Principles", RFC 7368, DOI 10.17487/RFC7368, October 2014, <https://www.rfc-editor.org/info/rfc7368>.
[RFC7368]Chown，T.，Ed.，Arkko，J.，Brandt，A.，Troan，O.，和J.Weil，“IPv6家庭网络架构原则”，RFC 7368，DOI 10.17487/RFC7368，2014年10月<https://www.rfc-editor.org/info/rfc7368>.
[RFC7513] Bi, J., Wu, J., Yao, G., and F. Baker, "Source Address Validation Improvement (SAVI) Solution for DHCP", RFC 7513, DOI 10.17487/RFC7513, May 2015, <https://www.rfc-editor.org/info/rfc7513>.
[RFC7513]Bi，J.，Wu，J.，Yao，G.，和F.Baker，“DHCP源地址验证改进（SAVI）解决方案”，RFC 7513，DOI 10.17487/RFC7513，2015年5月<https://www.rfc-editor.org/info/rfc7513>.
[RFC7550] Troan, O., Volz, B., and M. Siodelski, "Issues and Recommendations with Multiple Stateful DHCPv6 Options", RFC 7550, DOI 10.17487/RFC7550, May 2015, <https://www.rfc-editor.org/info/rfc7550>.
[RFC7550]Troan，O.，Volz，B.，和M.Siodelski，“多状态DHCPv6选项的问题和建议”，RFC 7550，DOI 10.17487/RFC7550，2015年5月<https://www.rfc-editor.org/info/rfc7550>.
[RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec, W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for Configuration of Softwire Address and Port-Mapped Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015, <https://www.rfc-editor.org/info/rfc7598>.
[RFC7598]Mrugalski，T.，Troan，O.，Farrer，I.，Perreault，S.，Dec，W.，Bao，C.，Yeh，L.，和X.Deng，“用于配置软线地址和端口映射客户端的DHCPv6选项”，RFC 7598，DOI 10.17487/RFC7598，2015年7月<https://www.rfc-editor.org/info/rfc7598>.
[RFC7610] Gont, F., Liu, W., and G. Van de Velde, "DHCPv6-Shield: Protecting against Rogue DHCPv6 Servers", BCP 199, RFC 7610, DOI 10.17487/RFC7610, August 2015, <https://www.rfc-editor.org/info/rfc7610>.
[RFC7610]Gont，F.，Liu，W.，和G.Van de Velde，“DHCPv6防护：防范恶意DHCPv6服务器”，BCP 199，RFC 7610，DOI 10.17487/RFC7610，2015年8月<https://www.rfc-editor.org/info/rfc7610>.
[RFC7707] Gont, F. and T. Chown, "Network Reconnaissance in IPv6 Networks", RFC 7707, DOI 10.17487/RFC7707, March 2016, <https://www.rfc-editor.org/info/rfc7707>.
[RFC7707]Gont，F.和T.Chown，“IPv6网络中的网络侦察”，RFC 7707，DOI 10.17487/RFC7707，2016年3月<https://www.rfc-editor.org/info/rfc7707>.
[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy Considerations for IPv6 Address Generation Mechanisms", RFC 7721, DOI 10.17487/RFC7721, March 2016, <https://www.rfc-editor.org/info/rfc7721>.
[RFC7721]Cooper，A.，Gont，F.，和D.Thaler，“IPv6地址生成机制的安全和隐私考虑”，RFC 7721，DOI 10.17487/RFC7721，2016年3月<https://www.rfc-editor.org/info/rfc7721>.
[RFC7824] Krishnan, S., Mrugalski, T., and S. Jiang, "Privacy Considerations for DHCPv6", RFC 7824, DOI 10.17487/RFC7824, May 2016, <https://www.rfc-editor.org/info/rfc7824>.
[RFC7824]Krishnan，S.，Mrugalski，T.，和S.Jiang，“DHCPv6的隐私考虑”，RFC 7824DOI 10.17487/RFC78242016年5月<https://www.rfc-editor.org/info/rfc7824>.
[RFC7844] Huitema, C., Mrugalski, T., and S. Krishnan, "Anonymity Profiles for DHCP Clients", RFC 7844, DOI 10.17487/RFC7844, May 2016, <https://www.rfc-editor.org/info/rfc7844>.
[RFC7844]Huitema，C.，Mrugalski，T.，和S.Krishnan，“DHCP客户端的匿名配置文件”，RFC 7844，DOI 10.17487/RFC7844，2016年5月<https://www.rfc-editor.org/info/rfc7844>.
[RFC7969] Lemon, T. and T. Mrugalski, "Customizing DHCP Configuration on the Basis of Network Topology", RFC 7969, DOI 10.17487/RFC7969, October 2016, <https://www.rfc-editor.org/info/rfc7969>.
[RFC7969]Lemon，T.和T.Mrugalski，“根据网络拓扑定制DHCP配置”，RFC 7969，DOI 10.17487/RFC7969，2016年10月<https://www.rfc-editor.org/info/rfc7969>.
[RFC8156] Mrugalski, T. and K. Kinnear, "DHCPv6 Failover Protocol", RFC 8156, DOI 10.17487/RFC8156, June 2017, <https://www.rfc-editor.org/info/rfc8156>.
[RFC8156]Mrugalski，T.和K.Kinnear，“DHCPv6故障切换协议”，RFC 8156，DOI 10.17487/RFC8156，2017年6月<https://www.rfc-editor.org/info/rfc8156>.
[RFC8168] Li, T., Liu, C., and Y. Cui, "DHCPv6 Prefix-Length Hint Issues", RFC 8168, DOI 10.17487/RFC8168, May 2017, <https://www.rfc-editor.org/info/rfc8168>.
[RFC8168]Li，T.，Liu，C.，和Y.Cui，“DHCPv6前缀长度提示问题”，RFC 8168，DOI 10.17487/RFC8168，2017年5月<https://www.rfc-editor.org/info/rfc8168>.
[TR-187] Broadband Forum, "TR-187 - IPv6 for PPP Broadband Access", February 2013, <https://www.broadband-forum.org/ technical/download/TR-187_Issue-2.pdf>.
[TR-187]宽带论坛，“TR-187-PPP宽带接入的IPv6”，2013年2月<https://www.broadband-forum.org/ 技术/下载/TR-187_Issue-2.pdf>。
This appendix provides a summary of the significant changes made to this updated DHCPv6 specification.
本附录总结了对更新后的DHCPv6规范所做的重大更改。
1. The Introduction (Section 1) was reorganized and updated. In particular, the client/server message exchanges were moved into a new (and expanded) section on their own (see Section 5).
1. 对导言（第1节）进行了重新组织和更新。特别是，客户机/服务器消息交换被单独移动到一个新的（和扩展的）部分（参见第5节）。
2. New sections were added to discuss the relationship to previous DHCPv6 documents and also to DHCPv4.
2. 增加了新的章节，以讨论与以前的DHCPv6文档以及与DHCPv4的关系。
3. Sections 2 ("Requirements") and 3 ("Background") had very minor edits.
3. 第2节（“要求”）和第3节（“背景”）有非常小的修改。
4. Section 4 ("Terminology") had minor edits.
4. 第4节（“术语”）进行了少量编辑。
5. Section 4.2 ("DHCP Terminology") was expanded to incorporate definitions from RFC 3633, add T1/T2 definitions, add definitions useful in describing combined address assignment and prefix delegation operations, and improve some existing definitions.
5. 第4.2节（“DHCP术语”）进行了扩展，以纳入RFC 3633中的定义，添加T1/T2定义，添加有助于描述组合地址分配和前缀委派操作的定义，并改进一些现有定义。
6. Section 5 ("Client/Server Exchanges") was added from material previously in Section 1 of RFC 3315 ("Introduction and Overview") and was expanded.
6. 第5节（“客户机/服务器交换”）是在RFC 3315（“简介和概述”）第1节之前的材料中添加的，并进行了扩展。
7. Section 6 ("Operational Models") is new. It provides information on the kinds of DHCP clients and how they operate.
7. 第6节（“运营模式”）是新的。它提供了有关DHCP客户端类型及其操作方式的信息。
8. Section 7 ("DHCP Constants") was primarily updated to add constants from RFC 4242 and RFC 7083. Note that the default HOP_COUNT_LIMIT value was reduced from 32 to 8.
8. 第7节（“DHCP常量”）主要更新为添加RFC 4242和RFC 7083中的常量。请注意，默认的跃点计数限制值已从32减少到8。
9. Sections 8 ("Client/Server Message Formats"), 9 ("Relay Agent/ Server Message Formats"), and 10 ("Representation and Use of Domain Names") had only very minor changes.
9. 第8节（“客户机/服务器消息格式”）、第9节（“中继代理/服务器消息格式”）和第10节（“域名的表示和使用”）仅作了很小的修改。
10. Section 11 ("DHCP Unique Identifier (DUID)") now discourages, rather than disallows, a server to parse the DUID; now includes some information on the DUID-UUID (RFC 6355); and had other minor edits.
10. 第11节（“DHCP唯一标识符（DUID）”）现在不鼓励而不是禁止服务器解析DUID；现在包括一些关于DUID-UUID（RFC 6355）的信息；还有其他一些小的修改。
11. Section 12 ("Identity Association") was expanded to better explain the concept and to also include prefix delegation.
11. 第12节（“身份协会”）被扩大，以更好地解释这一概念，并包括前缀授权。
12. Section 13 ("Assignment to an IA") incorporates material from two sections (11 and 12) of RFC 3315 and also includes a section on prefix delegation.
12. 第13节（“对IA的转让”）包含RFC 3315两节（第11节和第12节）中的材料，还包括一节关于授权的内容。
13. Section 14 ("Transmission of Messages by a Client") was expanded to include rate limiting by clients and how clients should handle T1 or T2 values of 0.
13. 第14节（“客户端的消息传输”）已扩展，包括客户端的速率限制以及客户端应如何处理0的T1或T2值。
14. Section 15 ("Reliability of Client-Initiated Message Exchanges") was expanded to clarify that the Elapsed Time option must be updated in retransmitted messages and that a client is not required to listen for DHCP traffic for the entire retransmission period.
14. 第15节（“客户机发起的消息交换的可靠性”）进行了扩展，以澄清必须在重新传输的消息中更新“运行时间”选项，并且不要求客户机在整个重新传输期间监听DHCP通信量。
15. Section 16 ("Message Validation") had minor edits.
15. 第16节（“消息验证”）有一些小的修改。
16. Section 17 ("Client Source Address and Interface Selection") was expanded to include prefix delegation.
16. 第17节（“客户机源地址和接口选择”）进行了扩展，包括前缀委托。
17. Section 18 ("DHCP Configuration Exchanges") consolidates what used to be in the following sections in RFC 3315: "DHCP Server Solicitation" (Section 17), "DHCP Client-Initiated Configuration Exchange" (Section 18), and "DHCP Server-Initiated Configuration Exchange" (Section 19). This material was reorganized and enhanced, and it incorporates prefix delegation from RFC 3633 and other changes from RFC 4242, RFC 7083, and RFC 7550. A few changes of note:
17. 第18节（“DHCP配置交换”）合并了RFC 3315中以下章节中的内容：“DHCP服务器请求”（第17节）、“DHCP客户端启动的配置交换”（第18节）和“DHCP服务器启动的配置交换”（第19节）。该材料经过重新组织和增强，并纳入了RFC 3633中的前缀委派以及RFC 4242、RFC 7083和RFC 7550中的其他更改。值得注意的几个变化：
A. The Option Request option is no longer optional for some messages (Solicit and Information-request), as RFC 7083 requires clients to request SOL_MAX_RT or INF_MAX_RT options.
A.对于某些消息（请求和信息请求），选项请求选项不再是可选的，因为RFC 7083要求客户端请求SOL_MAX_RT或INF_MAX_RT选项。
B. The Reconfigure message should no longer contain IA_NA/IA_PD, ORO, or other options to indicate to the client what was reconfigured. The client should request everything it needs in the response to the Reconfigure.
B.重新配置消息不应再包含IA_NA/IA_PD、ORO或其他选项，以向客户端指示重新配置的内容。客户端应在响应重新配置时请求所需的一切。
C. The lifetime and T1/T2 hints should not be sent by a client (it should send values of 0 in these fields), and any non-zero values should be ignored by the server.
C.客户端不应发送生存期和T1/T2提示（它应在这些字段中发送0的值），服务器应忽略任何非零值。
D. Clarified that a server may return different addresses in the Reply than requested by a client in the Request message. Also clarified that a server must not include addresses that it will not assign.
D.阐明服务器在回复中返回的地址可能与客户端在请求消息中请求的地址不同。还澄清了服务器不得包含其不会分配的地址。
Also, Section 18.2.12 ("Refreshing Configuration Information") was added to indicate use cases for when a client should try to refresh network information.
此外，添加了第18.2.12节（“刷新配置信息”），以指示客户端应尝试刷新网络信息的用例。
18. Section 19 ("Relay Agent Behavior") incorporates RFC 7283 and had minor edits. A new section, "Interaction between Relay Agents and Servers" (Section 19.4), was added.
18. 第19节（“中继代理行为”）包含RFC 7283，并进行了少量编辑。新增了一节“中继代理和服务器之间的交互”（第19.4节）。
19. Section 20 ("Authentication of DHCP Messages") includes significant changes: IPsec materials were mostly removed and replaced with a reference to RFC 8213, and the delayed authentication protocol has been obsoleted (see Section 25). Note that RKAP is still considered current.
19. 第20节（“DHCP消息的身份验证”）包括重大更改：IPsec材料大部分被删除并替换为参考RFC 8213，延迟身份验证协议已被废弃（见第25节）。请注意，RKAP仍然被认为是当前的。
20. Section 21 ("DHCP Options") was expanded to incorporate OPTION_IA_PD and OPTION_IAPREFIX from RFC 3633, the Information Refresh Time option (OPTION_INFORMATION_REFRESH_TIME) from RFC 4242, and the SOL_MAX_RT and INF_MAX_RT options from RFC 7083. Some additional edits were made to clarify option handling, such as which options should not be in an Option Request option.
20. 第21节（“DHCP选项”）扩展为包含RFC 3633中的选项IA_PD和选项IAU前缀、RFC 4242中的信息刷新时间选项（选项信息刷新时间）以及RFC 7083中的SOL_MAX_RT和INF_MAX_RT选项。进行了一些附加编辑以澄清选项处理，例如哪些选项不应出现在选项请求选项中。
21. The security considerations (Section 22) were updated to expand the discussion of security threats and include material from the incorporated documents, primarily RFC 3633.
21. 更新了安全注意事项（第22节），以扩大对安全威胁的讨论，并包括合并文件（主要是RFC 3633）中的材料。
22. New privacy considerations were added (Section 23) to account for privacy issues.
22. 增加了新的隐私注意事项（第23节），以说明隐私问题。
23. Section 24 ("IANA Considerations") was rewritten to reflect the changes requested for this document, as other documents have already made the message, option, DUID, and status code assignments and this document does not add any new assignments.
23. 第24节（“IANA注意事项”）已重写，以反映本文件要求的变更，因为其他文件已对消息、选项、DUID和状态代码进行了分配，且本文件未添加任何新的分配。
24. Section 25 ("Obsoleted Mechanisms") is a new section that documents the mechanisms obsoleted by this specification.
24. 第25节（“废弃机制”）是一个新的章节，记录了本规范中废弃的机制。
25. Appendices B ("Appearance of Options in Message Types") and C ("Appearance of Options in the "options" Field of DHCP Options") were updated to reflect the incorporated options from RFC 3633, RFC 4242, and RFC 7083.
25. 附录B（“消息类型中的选项外观”）和C（“DHCP选项的“选项”字段中的选项外观”）已更新，以反映RFC 3633、RFC 4242和RFC 7083中合并的选项。
26. Where appropriate, informative references have been added to provide further background and guidance throughout the document (as can be noted by the vast increase in references).
26. 在适当的情况下，增加了资料性参考文献，以在整个文件中提供进一步的背景和指导（参考文献的大量增加说明了这一点）。
27. Changes were made to incorporate the following errata for RFC 3315: Erratum IDs 294, 295, 1373, 1815, 2471, 2472, 2509, 2928, 3577, 5450; RFC 3633: Erratum IDs 248, 2468, 2469, 2470, 3736; and RFC 3736: Erratum ID 3796. Note that Erratum ID 1880 for RFC 3633 no longer applies, as servers (delegating routers) ignore received T1/T2 hints (see (C) in item 17 above).
27. 对RFC 3315的以下勘误表进行了修改：勘误表ID 294、295、1373、1815、2471、2472、2509、2928、3577、5450；RFC 3633：勘误表IDs 248、2468、2469、2470、3736；和RFC 3736：勘误表ID 3796。请注意，RFC 3633的勘误表ID 1880不再适用，因为服务器（委托路由器）忽略收到的T1/T2提示（请参见上文第17项中的（C））。
28. General changes to other IPv6 specifications, such as removing the use of site-local unicast addresses and adding unique local addresses, were made to the document.
28. 对其他IPv6规范进行了一般性更改，如删除站点本地单播地址的使用和添加唯一的本地地址。
29. It should be noted that this document does not refer to all DHCPv6 functionality and specifications. Readers of this specification should visit <https://www.iana.org/assignments/ dhcpv6-parameters> and <https://datatracker.ietf.org/wg/dhc/> to learn of the RFCs that define DHCPv6 messages, options, status codes, and more.
29. 应该注意的是，本文档并未提及所有DHCPv6功能和规范。本规范的读者应访问<https://www.iana.org/assignments/ dhcpv6参数>和<https://datatracker.ietf.org/wg/dhc/>了解定义DHCPv6消息、选项、状态代码等的RFC。
The following tables indicate with a "*" the options that are allowed in each DHCP message type.
下表用“*”表示每个DHCP消息类型中允许的选项。
These tables are informational. If they conflict with text earlier in this document, that text should be considered authoritative.
这些表格提供了信息。如果它们与本文件前面的文本冲突，则该文本应被视为具有权威性。
Client Server IA_NA/ Elap. Relay Server
ID ID IA_TA IA_PD ORO Pref Time Msg. Auth. Unicast
Solicit * * * * *
Advert. * * * * *
Request * * * * * *
Confirm * * *
Renew * * * * * *
Rebind * * * * *
Decline * * * * *
Release * * * * *
Reply * * * * * *
Reconf. * * *
Inform. * (see note) * *
R-forw. *
R-repl. *
Client Server IA_NA/ Elap. Relay Server
ID ID IA_TA IA_PD ORO Pref Time Msg. Auth. Unicast
Solicit * * * * *
Advert. * * * * *
Request * * * * * *
Confirm * * *
Renew * * * * * *
Rebind * * * * *
Decline * * * * *
Release * * * * *
Reply * * * * * *
Reconf. * * *
Inform. * (see note) * *
R-forw. *
R-repl. *
NOTE: The Server Identifier option (see Section 21.3) is only included in Information-request messages that are sent in response to a Reconfigure (see Section 18.2.6).
注：服务器标识符选项（见第21.3节）仅包含在响应重新配置而发送的信息请求消息中（见第18.2.6节）。
Info
Status Rap. User Vendor Vendor Inter. Recon. Recon. Refresh
Code Comm. Class Class Spec. ID Msg. Accept Time
Solicit * * * * *
Advert. * * * * *
Request * * * *
Confirm * * *
Renew * * * *
Rebind * * * *
Decline * * *
Release * * *
Reply * * * * * * *
Reconf. *
Inform. * * * *
R-forw. * *
R-repl. * *
Info
Status Rap. User Vendor Vendor Inter. Recon. Recon. Refresh
Code Comm. Class Class Spec. ID Msg. Accept Time
Solicit * * * * *
Advert. * * * * *
Request * * * *
Confirm * * *
Renew * * * *
Rebind * * * *
Decline * * *
Release * * *
Reply * * * * * * *
Reconf. *
Inform. * * * *
R-forw. * *
R-repl. * *
SOL_MAX_RT INF_MAX_RT Solicit Advert. * Request Confirm Renew Rebind Decline Release Reply * * Reconf. Inform. R-forw. R-repl.
SOL_MAX_RT INF_MAX_RT征求广告。*请求确认续订重新绑定拒绝释放回复**重新确认。知会R-forw。R-repl。
Appendix C. Appearance of Options in the "options" Field of DHCP Options
附录C.DHCP选项“选项”字段中选项的外观
The following table indicates with a "*" where options defined in this document can appear as top-level options or can be encapsulated in other options defined in this document. Other RFCs may define additional situations where options defined in this document are encapsulated in other options.
下表用“*”表示本文档中定义的选项可以显示为顶级选项，也可以封装在本文档中定义的其他选项中。其他RFC可能会定义本文件中定义的选项封装在其他选项中的其他情况。
This table is informational. If it conflicts with text earlier in this document, that text should be considered authoritative.
此表仅供参考。如果与本文件前面的文本冲突，则该文本应被视为具有权威性。
Top- IA_NA/ RELAY- RELAY-
Level IA_TA IAADDR IA_PD IAPREFIX FORW REPL
Client ID *
Server ID *
IA_NA/IA_TA *
IAADDR *
IA_PD *
IAPREFIX *
ORO *
Preference *
Elapsed Time *
Relay Message * *
Authentic. *
Server Uni. *
Status Code * * *
Rapid Comm. *
User Class *
Vendor Class *
Vendor Info. * * *
Interf. ID * *
Reconf. MSG. *
Reconf. Accept *
Info Refresh Time *
SOL_MAX_RT *
INF_MAX_RT *
Top- IA_NA/ RELAY- RELAY-
Level IA_TA IAADDR IA_PD IAPREFIX FORW REPL
Client ID *
Server ID *
IA_NA/IA_TA *
IAADDR *
IA_PD *
IAPREFIX *
ORO *
Preference *
Elapsed Time *
Relay Message * *
Authentic. *
Server Uni. *
Status Code * * *
Rapid Comm. *
User Class *
Vendor Class *
Vendor Info. * * *
Interf. ID * *
Reconf. MSG. *
Reconf. Accept *
Info Refresh Time *
SOL_MAX_RT *
INF_MAX_RT *
Notes: Options asterisked in the "Top-Level" column appear in the "options" field of client messages (see Section 8). Options asterisked in the "RELAY-FORW" and "RELAY-REPL" columns appear in the "options" field of the Relay-forward and Relay-reply messages (see Section 9).
注：“顶层”列中带星号的选项出现在客户端消息的“选项”字段中（参见第8节）。中继转发和中继回复消息的“选项”字段中出现“中继转发”和“中继回复”列中标有星号的选项（参见第9节）。
Acknowledgments
致谢
This document is merely a refinement of earlier work by the authors of the following documents and would not be possible without their original work:
本文件仅是以下文件的作者对早期工作的改进，如果没有他们的原始工作，将不可能：
- RFC 3315 (Ralph Droms, Jim Bound, Bernie Volz, Ted Lemon, Charles Perkins, and Mike Carney)
- RFC 3315（拉尔夫·德罗姆斯、吉姆·邦德、伯尼·沃尔兹、特德·莱蒙、查尔斯·帕金斯和迈克·卡尼）
- RFC 3633 (Ole Troan and Ralph Droms)
- RFC 3633（Ole Troan和Ralph Droms）
- RFC 3736 (Ralph Droms)
- RFC 3736（拉尔夫·德罗姆斯）
- RFC 4242 (Stig Venaas, Tim Chown, and Bernie Volz)
- RFC 4242（Stig Venaas、Tim Chown和Bernie Volz）
- RFC 7083 (Ralph Droms)
- RFC 7083（拉尔夫·德罗姆斯）
- RFC 7283 (Yong Cui, Qi Sun, and Ted Lemon)
- RFC 7283（崔勇、孙琦和特德·莱蒙）
- RFC 7550 (Ole Troan, Bernie Volz, and Marcin Siodelski)
- RFC 7550（Ole Troan、Bernie Volz和Marcin Siodelski）
A number of additional people have contributed to identifying issues with RFC 3315 and RFC 3633 and proposed resolutions to these issues as reflected in this document (listed here in no particular order): Ole Troan, Robert Marks, Leaf Yeh, Michelle Cotton, Pablo Armando, John Brzozowski, Suresh Krishnan, Hideshi Enokihara, Alexandru Petrescu, Yukiyo Akisada, Tatuya Jinmei, Fred Templin, and Christian Huitema.
另外一些人帮助确定了RFC 3315和RFC 3633的问题，并提出了本文件中反映的这些问题的解决方案（此处未按特定顺序列出）：Ole Troan、Robert Marks、Leaf Yeh、Michelle Cotton、Pablo Armando、John Brzowski、Suresh Krishnan、Hideshi Enokihara、Alexandru Petrescu、，秋田由纪夫、塔图亚·金梅、弗雷德·坦普林和克里斯蒂安·惠特玛。
We also thank the following, not otherwise acknowledged and in no particular order, for their review comments: Jeremy Reed, Francis Dupont, Lorenzo Colitti, Tianxiang Li, Ian Farrer, Yogendra Pal, Kim Kinnear, Shawn Routhier, Michayla Newcombe, Alissa Cooper, Allison Mankin, Adam Roach, Kyle Rose, Elwyn Davies, Eric Rescorla, Ben Campbell, Warren Kumari, and Kathleen Moriarty.
我们还感谢以下未另行确认且无特殊顺序的审查意见：杰里米·里德、弗朗西斯·杜邦、洛伦佐·科利蒂、李天祥、伊恩·法勒、约根德拉·帕尔、金·金尼尔、肖恩·劳希尔、米夏拉·纽科姆贝、艾莉莎·库珀、艾莉森·曼金、亚当·罗奇、凯尔·罗斯、埃尔温·戴维斯、埃里克·雷斯科拉、本·坎贝尔、，沃伦·库马里和凯瑟琳·莫里亚蒂。
Also, special thanks to Ralph Droms for answering many questions related to the original RFC 3315 and RFC 3633 work and for shepherding this document through the IETF process.
另外，特别感谢拉尔夫·德罗姆斯回答了许多与原始RFC 3315和RFC 3633工作相关的问题，并通过IETF流程指导了本文件。
Authors' Addresses
作者地址
Tomek Mrugalski Internet Systems Consortium, Inc. 950 Charter Street Redwood City, CA 94063 United States of America
美国加利福尼亚州红木市Charter Street 950号Tomek Mrugalski Internet Systems Consortium，Inc.94063
Email: tomasz.mrugalski@gmail.com
Email: tomasz.mrugalski@gmail.com
Marcin Siodelski Internet Systems Consortium, Inc. 950 Charter Street Redwood City, CA 94063 United States of America
Marcin Siodelski Internet Systems Consortium，Inc.美国加利福尼亚州红木市Charter Street 950号，邮编94063
Email: msiodelski@gmail.com
Email: msiodelski@gmail.com
Bernie Volz Cisco Systems, Inc. 1414 Massachusetts Ave. Boxborough, MA 01719 United States of America
Bernie Volz Cisco Systems，Inc.美国马萨诸塞州Boxborough大道1414号，邮编01719
Email: volz@cisco.com
Email: volz@cisco.com
Andrew Yourtchenko Cisco Systems, Inc. De kleetlaan 6a Diegem BRABANT 1831 Belgium
Andrew Yourtchenko Cisco Systems，Inc.De kleetlaan 6a Diegem BRABANT 1831比利时
Email: ayourtch@cisco.com
Email: ayourtch@cisco.com
Michael C. Richardson Sandelman Software Works 470 Dawson Avenue Ottawa, ON K1Z 5V7 Canada
Michael C.Richardson Sandelman软件公司位于加拿大K1Z 5V7的渥太华道森大道470号
Email: mcr+ietf@sandelman.ca
URI: http://www.sandelman.ca/
Email: mcr+ietf@sandelman.ca
URI: http://www.sandelman.ca/
Sheng Jiang Huawei Technologies Co., Ltd Q14, Huawei Campus, No. 156 Beiqing Road Hai-Dian District, Beijing 100095 China
中国北京海淀区北青路156号华为校园盛江华为技术有限公司Q14，邮编100095
Email: jiangsheng@huawei.com
Email: jiangsheng@huawei.com
Ted Lemon Nibbhaya Consulting P.O. Box 958 Brattleboro, VT 05301-0958 United States of America
Ted Lemon Nibbhaya Consulting美国VT 05301-0958布拉特波罗958号邮政信箱
Email: mellon@fugue.com
Email: mellon@fugue.com
Timothy Winters University of New Hampshire, Interoperability Lab (UNH-IOL) Durham, NH United States of America
新罕布什尔大学，互操作实验室（UH-IOL）达勒姆，美利坚合众国
Email: twinters@iol.unh.edu
Email: twinters@iol.unh.edu