Network Working Group G. Bajko
Request for Comments: 5678 Nokia
Category: Standards Track S. Das
Telcordia Technologies Inc.
December 2009
Network Working Group G. Bajko
Request for Comments: 5678 Nokia
Category: Standards Track S. Das
Telcordia Technologies Inc.
December 2009
Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) Options for IEEE 802.21 Mobility Services (MoS) Discovery
用于IEEE 802.21移动服务（MoS）发现的动态主机配置协议（DHCPv4和DHCPv6）选项
Abstract
摘要
This document defines new Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) options that contain a list of IP addresses and a list of domain names that can be mapped to servers providing IEEE 802.21 type of Mobility Service (MoS) (see RFC 5677). These Mobility Services are used to assist a mobile node (MN) in handover preparation (network discovery) and handover decision (network selection). The services addressed in this document are the Media Independent Handover Services defined in IEEE 802.21.
本文档定义了新的动态主机配置协议（DHCPv4和DHCPv6）选项，其中包含可映射到提供IEEE 802.21类型移动服务（MoS）的服务器的IP地址列表和域名列表（请参阅RFC 5677）。这些移动服务用于协助移动节点（MN）进行切换准备（网络发现）和切换决策（网络选择）。本文档中涉及的服务是IEEE 802.21中定义的与媒体无关的切换服务。
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2009 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 (http://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 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(http://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许可文本，并且提供BSD许可中所述的代码组件时不提供任何担保。
Table of Contents
目录
1. Introduction ....................................................2
1.1. Conventions Used in This Document ..........................3
1.2. Terminology ................................................3
2. MoS IPv4 Address Option for DHCPv4 ..............................3
3. MoS Domain Name List Option for DHCPv4 ..........................5
4. MoS IPv6 Address Option for DHCPv6 ..............................7
5. MoS Domain Name List Option for DHCPv6 ..........................9
6. Option Usage ...................................................10
6.1. Usage of MoS Options for DHCPv4 ...........................10
6.2. Usage of MoS Options for DHCPv6 ...........................11
7. Security Considerations ........................................12
8. IANA Considerations ............................................12
9. Acknowledgements ...............................................13
10. References ....................................................13
10.1. Normative References .....................................13
10.2. Informative References ...................................14
1. Introduction ....................................................2
1.1. Conventions Used in This Document ..........................3
1.2. Terminology ................................................3
2. MoS IPv4 Address Option for DHCPv4 ..............................3
3. MoS Domain Name List Option for DHCPv4 ..........................5
4. MoS IPv6 Address Option for DHCPv6 ..............................7
5. MoS Domain Name List Option for DHCPv6 ..........................9
6. Option Usage ...................................................10
6.1. Usage of MoS Options for DHCPv4 ...........................10
6.2. Usage of MoS Options for DHCPv6 ...........................11
7. Security Considerations ........................................12
8. IANA Considerations ............................................12
9. Acknowledgements ...............................................13
10. References ....................................................13
10.1. Normative References .....................................13
10.2. Informative References ...................................14
IEEE 802.21 [IEEE802.21] defines three distinct service types to facilitate link layer handovers across heterogeneous technologies:
IEEE 802.21[IEEE802.21]定义了三种不同的服务类型，以促进跨异构技术的链路层切换：
a) Information Services (IS) IS provides a unified framework to the higher-layer entities across the heterogeneous network environment to facilitate discovery and selection of multiple types of networks existing within a geographical area. The objective is to help the higher-layer mobility protocols acquire a global view of heterogeneous networks and perform seamless handover across these networks.
a) 信息服务（IS）为异构网络环境中的高层实体提供了统一的框架，以便于发现和选择地理区域内存在的多种类型的网络。其目标是帮助高层移动协议获得异构网络的全局视图，并在这些网络之间执行无缝切换。
b) Event Services (ES) Events may indicate changes in state and transmission behavior of the physical, data link, and logical link layers, or predict state changes of these layers. The Event Service may also be used to indicate management actions or command status on the part of the network or some management entity.
b) 事件服务（ES）事件可指示物理、数据链路和逻辑链路层的状态和传输行为的变化，或预测这些层的状态变化。事件服务还可用于指示网络或某些管理实体的管理操作或命令状态。
c) Command Services (CS) The command service enables higher layers to control the physical, data link, and logical link layers. The higher layers may control the reconfiguration or selection of an appropriate link through a set of handover commands.
c) 命令服务（CS）命令服务使更高层能够控制物理层、数据链路层和逻辑链路层。更高层可以通过一组切换命令来控制适当链路的重新配置或选择。
In IEEE terminology, these services are called Media Independent Handover (MIH) services. While these services may be co-located, the different pattern and type of information they provide do not necessitate the co-location.
在IEEE术语中，这些服务称为媒体独立切换（MIH）服务。虽然这些服务可能位于同一地点，但它们提供的不同模式和类型的信息并不需要位于同一地点。
A mobile node (MN) may make use of any of these MIH service types separately or any combination of them [RFC5677]. In practice, a Mobility Server may not necessarily host all three of these MIH services together; thus, there is a need to discover the MIH service types separately.
移动节点（MN）可以单独使用这些MIH服务类型中的任何一种或它们的任何组合[RFC5677]。在实践中，移动服务器不一定同时承载这三个MIH服务；因此，需要单独发现MIH服务类型。
This document defines new DHCPv4 and DHCPv6 options and sub-options called the MoS IP Address and Domain Name List Options, which allow the MN to locate a Mobility Server that hosts the desired service type (i.e., IS, ES, or CS) as defined in [IEEE802.21]. Apart from manual configuration, this is one of the possible solutions for locating a server providing Mobility Services.
本文档定义了新的DHCPv4和DHCPv6选项以及称为MoS IP地址和域名列表选项的子选项，允许MN定位承载[IEEE802.21]中定义的所需服务类型（即IS、ES或CS）的移动服务器。除了手动配置之外，这是定位提供移动服务的服务器的可能解决方案之一。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
Mobility Services: a set of services provided by the network to mobile nodes to facilitate handover preparation and handover decision. In this document, Mobility Services refer to the services defined in IEEE 802.21 specifications [IEEE802.21]
移动性服务：网络向移动节点提供的一组服务，以便于切换准备和切换决策。在本文档中，移动服务指IEEE 802.21规范[IEEE802.21]中定义的服务
Mobility Server: a network node providing Mobility Services.
移动服务器：提供移动服务的网络节点。
MIH: Media Independent Handover, as defined in [IEEE802.21].
MIH:IEEE802.21中定义的媒体独立切换。
MIH Service: IS, ES, or CS type of service, as defined in [IEEE802.21].
MIH服务：指[IEEE802.21]中定义的IS、ES或CS类型的服务。
This section describes the MoS IPv4 Address Option for DHCPv4. Whether the MN receives a MoS address from the local or home network will depend on the actual network deployment [RFC5677]. The MoS IPv4 Address Option begins with an option code followed by a length and sub-options. The value of the length octet does not include itself or the option code. The option layout is depicted below:
本节介绍DHCPv4的MoS IPv4地址选项。MN是否从本地或家庭网络接收MoS地址取决于实际网络部署[RFC5677]。MoS IPv4地址选项以选项代码开头，后跟长度和子选项。长度八位字节的值不包括其本身或选项代码。选项布局如下所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option Code
选项代码
OPTION-IPv4_Address-MoS (139) - 1 byte
选项-IPv4_地址-MoS（139）-1字节
Length
长
An 8-bit field indicating the length of the option excluding the 'Option Code' and the 'Length' fields
一个8位字段，指示选项的长度，不包括“选项代码”和“长度”字段
Sub-options
子选项
A series of DHCPv4 sub-options
一系列DHCPv4子选项
When the total length of a MoS IPv4 Address Option exceeds 254 octets, the procedure outlined in [RFC3396] MUST be employed to split the option into multiple, smaller options.
当MoS IPv4地址选项的总长度超过254个八位字节时，必须采用[RFC3396]中概述的程序将该选项拆分为多个较小的选项。
A sub-option begins with a sub-option code followed by a length and one or more IPv4 addresses. The sub-option layout is depicted below:
子选项以子选项代码开头，后跟长度和一个或多个IPv4地址。子选项布局如下图所示：
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 | Length | IP Address . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length | IP Address . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The sub-option codes are summarized below.
子选项代码汇总如下。
+--------------+---------------+
| Sub-opt | Service |
| Code | Name |
+==============+===============+
| 1 | IS |
+--------------+---------------+
| 2 | CS |
+--------------+---------------+
| 3 | ES |
+--------------+---------------+
+--------------+---------------+
| Sub-opt | Service |
| Code | Name |
+==============+===============+
| 1 | IS |
+--------------+---------------+
| 2 | CS |
+--------------+---------------+
| 3 | ES |
+--------------+---------------+
If the length is followed by a list of IPv4 addresses indicating appropriate MIH servers available to the MN for a requested option, servers MUST be listed in order of preference and the client should process them in decreasing order of preference. In the case that there is no MIH server available, the length is set to 0; otherwise, it is a multiple of 4.
如果长度后面是IPv4地址列表，指示MN可用于请求选项的适当MIH服务器，则必须按首选顺序列出服务器，客户端应按首选顺序递减处理这些服务器。如果没有可用的MIH服务器，则长度设置为0；否则，它是4的倍数。
The sub-option has the following format:
子选项具有以下格式：
Code Len IPv4 Address 1 IPv4 Address 2
+-----+---+---+----+----+----+----+----+---
|1..3 | n |a1 | a2 |a3 | a4 | a1 | ...
+-----+---+---+----+----+----+-----+----+--
Code Len IPv4 Address 1 IPv4 Address 2
+-----+---+---+----+----+----+----+----+---
|1..3 | n |a1 | a2 |a3 | a4 | a1 | ...
+-----+---+---+----+----+----+-----+----+--
This section describes the MoS Domain Name List Option for DHCPv4. The general format of this option is depicted below:
本节介绍DHCPv4的MoS域名列表选项。该选项的一般格式如下所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option Code
选项代码
OPTION-IPv4_FQDN-MoS (140) - 1 byte
选项-IPv4_FQDN-MoS（140）-1字节
Length
长
An 8-bit field indicating the length of the option excluding the 'Option Code' and the 'Length' fields
一个8位字段，指示选项的长度，不包括“选项代码”和“长度”字段
Sub-options
子选项
A series of DHCPv4 sub-options.
一系列DHCPv4子选项。
When the total length of a MoS Domain Name List Option exceeds 254 octets, the procedure outlined in [RFC3396] MUST be employed to split the option into multiple, smaller options.
当MoS域名列表选项的总长度超过254个八位字节时，必须采用[RFC3396]中概述的程序将该选项拆分为多个较小的选项。
A sub-option begins with a sub-option code followed by a length and one or more Fully Qualified Domain Names (FQDNs). The sub-option layout is depicted below:
子选项以子选项代码开头，后跟长度和一个或多个完全限定域名（FQDN）。子选项布局如下图所示：
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 | Length | FQDN(s) . . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length | FQDN(s) . . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The sub-option codes are summarized below.
子选项代码汇总如下。
+--------------+---------------+
| Sub-opt | Service |
| Code | Name |
+==============+===============+
| 1 | IS |
+--------------+---------------+
| 2 | CS |
+--------------+---------------+
| 3 | ES |
+--------------+---------------+
+--------------+---------------+
| Sub-opt | Service |
| Code | Name |
+==============+===============+
| 1 | IS |
+--------------+---------------+
| 2 | CS |
+--------------+---------------+
| 3 | ES |
+--------------+---------------+
Thus, the sub-option for this encoding has the following format:
因此，此编码的子选项具有以下格式：
Code Len DNS name of Mobility Server
+-----+----+----+-----+-----+-----+-----+--
|1..3 | n | s1 | s2 | s3 | s4 | s5 | ...
+-----+----+----+-----+-----+-----+-----+--
Code Len DNS name of Mobility Server
+-----+----+----+-----+-----+-----+-----+--
|1..3 | n | s1 | s2 | s3 | s4 | s5 | ...
+-----+----+----+-----+-----+-----+-----+--
The sub-option begins with a sub-option code followed by a length and a sequence of labels that are encoded according to Section 8 of [RFC3315].
子选项以子选项代码开头，后跟根据[RFC3315]第8节编码的长度和标签序列。
The sub-option MAY contain multiple domain names, but these should refer to the NAPTR records of different providers, rather than different A records within the same provider. That is, the use of multiple domain names is not meant to replace NAPTR and SRV records, but rather to allow a single DHCP server to indicate MIH servers operated by multiple providers.
子选项可能包含多个域名，但这些域名应指不同提供商的NAPTR记录，而不是同一提供商内的不同A记录。也就是说，使用多个域名并不意味着替换NAPTR和SRV记录，而是允许单个DHCP服务器指示由多个提供商操作的MIH服务器。
The client MUST try the records in the order listed, applying the mechanism described in [RFC5679] for each. The client only resolves the subsequent domain names if attempts to contact the first one failed or yielded no common transport protocols between the MN and the server.
客户端必须按照列出的顺序尝试记录，并对每个记录应用[RFC5679]中描述的机制。如果尝试联系第一个域名失败或在MN和服务器之间没有产生公共传输协议，则客户端仅解析后续域名。
As an example, consider the case where the server wants to offer two MIH IS servers, "example.com" and "example.net". These would be encoded as follows:
举个例子，考虑服务器想要提供两个MIH服务器的例子：“示例.com”和“示例.NET”。这些将被编码如下：
+-----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|1..3 |26 | 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'c'|'o'|'m'| 0 |
+-----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'n'|'e'|'t'| 0 |
+---+---+---+---+---+---+---+---+---+---+---+---+---+
+-----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|1..3 |26 | 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'c'|'o'|'m'| 0 |
+-----+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 7 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| 3 |'n'|'e'|'t'| 0 |
+---+---+---+---+---+---+---+---+---+---+---+---+---+
This section describes the MoS IPv6 Address Option for DHCPv6. Whether the MN receives a MoS address from the local or home network will depend on the actual network deployment [RFC5677]. The MoS Discovery Option begins with an option code followed by a length and sub-options. The value of the length octet does not include itself or the option code. The option layout is depicted below:
本节介绍DHCPv6的MoS IPv6地址选项。MN是否从本地或家庭网络接收MoS地址取决于实际网络部署[RFC5677]。MoS查找选项以选项代码开头，后跟长度和子选项。长度八位字节的值不包括其本身或选项代码。选项布局如下所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option Code
选项代码
OPTION-IPv6_Address-MoS (54) - 2 bytes
选项-IPv6_地址-MoS（54）-2字节
Length
长
A 16-bit field indicating the length of the option excluding the 'Option Code' and the 'Length' fields.
一个16位字段，指示选项的长度，不包括“选项代码”和“长度”字段。
Sub-options
子选项
A series of DHCPv6 sub-options
一系列DHCPv6子选项
The sub-options follow the same format (except the Sub-opt Code and Length value) as described in Section 2. The value of the Sub-opt Code and Length is 2 octets, and the Length does not include itself or the Sub-opt Code field. The sub-option layout is depicted below:
子选项采用第2节所述的相同格式（子选项代码和长度值除外）。子选项代码和长度的值为2个八位字节，长度不包括自身或子选项代码字段。子选项布局如下图所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Address |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Address |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The sub-option codes are summarized below.
子选项代码汇总如下。
+----------------+---------------+
| Sub-opt Code | Service Name |
+================+===============+
| 1 | IS |
+----------------+---------------+
| 2 | CS |
+----------------+---------------+
| 3 | ES |
+----------------+---------------+
+----------------+---------------+
| Sub-opt Code | Service Name |
+================+===============+
| 1 | IS |
+----------------+---------------+
| 2 | CS |
+----------------+---------------+
| 3 | ES |
+----------------+---------------+
If the length is followed by a list of IPv6 addresses indicating appropriate MIH servers available to the MN for a requested option, servers MUST be listed in order of preference and the client should
如果长度后面是IPv6地址列表，指示MN可用于请求选项的适当MIH服务器，则必须按优先顺序列出服务器，并且客户端应
process them in decreasing order of preference. In the case where there is no MIH server available, the length is set to 0; otherwise, it is a multiple of 16.
按偏好的降序处理它们。如果没有可用的MIH服务器，则长度设置为0；否则，它是16的倍数。
This section describes the MoS Domain List Option for DHCPv6. The general format of this option is depicted below:
本节介绍DHCPv6的MoS域列表选项。该选项的一般格式如下所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option 1 |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Option n |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option Code
选项代码
OPTION-IPv6_FQDN-MoS (55) - 2 bytes
选项-IPv6_FQDN-MoS（55）-2字节
Length
长
A 16-bit field indicating the length of the option excluding the 'Option Code' and the 'Length' fields
一个16位字段，指示选项的长度，不包括“选项代码”和“长度”字段
Sub-options
子选项
A series of DHCPv6 sub-options
一系列DHCPv6子选项
The sub-options follow the same format (except the Sub-opt Code and Length value) as described in Section 3. The value of the Sub-opt Code and Length is 2 octets, and the Length does not include itself or the Sub-opt Code field. The sub-option layout is depicted below:
子选项采用第3节所述的相同格式（子选项代码和长度值除外）。子选项代码和长度的值为2个八位字节，长度不包括自身或子选项代码字段。子选项布局如下图所示：
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FQDN(s) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FQDN(s) |
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The sub-option codes are summarized below.
子选项代码汇总如下。
+----------------+---------------+
| Sub-opt Code | Service Name |
+================+===============+
| 1 | IS |
+----------------+---------------+
| 2 | CS |
+----------------+---------------+
| 3 | ES |
+----------------+---------------+
+----------------+---------------+
| Sub-opt Code | Service Name |
+================+===============+
| 1 | IS |
+----------------+---------------+
| 2 | CS |
+----------------+---------------+
| 3 | ES |
+----------------+---------------+
The semantics and content of the DHCPv6 encoding of this option are exactly the same as the encoding described in Section 3, except the Option Code and Length value.
除了选项代码和长度值之外，该选项的DHCPv6编码的语义和内容与第3节中描述的编码完全相同。
The requesting and sending of the proposed DHCPv4 options follow the rules for DHCP options in [RFC2131].
建议的DHCPv4选项的请求和发送遵循[RFC2131]中DHCP选项的规则。
The mobile node may perform a MoS discovery either during initial association with a network or when the mobility service is required. It may also try to perform the MoS discovery when it lacks the network information for MoS or needs to change the MoS for some reasons, for instance, to recover from the single point of failure of the existing MoS.
移动节点可以在与网络的初始关联期间或者在需要移动服务时执行MoS发现。当它缺少MoS的网络信息或出于某些原因需要更改MoS时，例如，为了从现有MoS的单点故障中恢复，它也可能尝试执行MoS发现。
In order to discover the IP address or FQDN of a MoS, the mobile node (DHCP client) MUST include either a MoS IPv4 Address Option or a MoS Domain Name List Option in the Parameter Request List (PRL) in the respective DHCP messages as defined in [RFC2131].
为了发现MoS的IP地址或FQDN，移动节点（DHCP客户端）必须在[RFC2131]中定义的相应DHCP消息的参数请求列表（PRL）中包含MoS IPv4地址选项或MoS域名列表选项。
The client MAY include a MoS IPv4 Address Option or a MoS Domain Name List Option that includes one or more sub-option(s) with the Sub-opt Code or Codes that represent the service(s) the mobile node is interested in. However, a client SHOULD be prepared to accept a response from a server that includes other sub-option(s) or does not include the requested sub-option(s).
客户端可以包括MoS IPv4地址选项或MoS域名列表选项，该选项包括一个或多个子选项，该子选项具有表示移动节点感兴趣的服务的子选项代码。但是，客户机应准备接受来自包含其他子选项或不包含请求的子选项的服务器的响应。
When the DHCP server receives either a MoS IPv4 Address Option or a MoS Domain Name List Option in the PRL, the DHCP server MUST include the option in its response message as defined in [RFC2131].
当DHCP服务器在PRL中接收到MoS IPv4地址选项或MoS域名列表选项时，DHCP服务器必须按照[RFC2131]中的定义在其响应消息中包含该选项。
A server MAY use the sub-options in the received MoS IPv4 Address Option or MoS Domain Name List Option from the client's message to restrict its response to the client requested sub-options. In the case when the server cannot find any Mobility Server satisfying a requested sub-option, the server SHOULD return the MoS Option with that sub-option and the length of the sub-option set to 0.
服务器可以使用客户端消息中接收的MoS IPv4地址选项或MoS域名列表选项中的子选项来限制其对客户端请求的子选项的响应。如果服务器找不到任何满足请求的子选项的移动服务器，则服务器应返回MoS选项，并将该子选项和子选项的长度设置为0。
The requesting and sending of the proposed DHCPv6 options follow the rules for DHCP options in [RFC3315].
建议的DHCPv6选项的请求和发送遵循[RFC3315]中DHCP选项的规则。
The mobile node may perform the MoS discovery either during initial association with a network or when the mobility service is required. It may also try to perform the MoS discovery when it lacks the network information for MoS or needs to change the MoS for some reasons, for instance, to recover from the single point of failure of the existing MoS.
移动节点可以在与网络的初始关联期间或者在需要移动服务时执行MoS发现。当它缺少MoS的网络信息或出于某些原因需要更改MoS时，例如，为了从现有MoS的单点故障中恢复，它也可能尝试执行MoS发现。
In order to discover the IP address or FQDN of a MoS, the mobile node (DHCP client) MUST include either a MoS IPv6 Address Option or a MoS Domain Name List Option in the Option Request Option (ORO) in the respective DHCP messages as defined in [RFC3315].
为了发现MoS的IP地址或FQDN，移动节点（DHCP客户端）必须在[RFC3315]中定义的相应DHCP消息中的选项请求选项（ORO）中包含MoS IPv6地址选项或MoS域名列表选项。
The client MAY include a MoS IPv6 Address Option or a MoS Domain Name List Option that includes one or more sub-option(s) with the Sub-opt Code or Codes that represent the service(s) the mobile node is
客户端可以包括MoS IPv6地址选项或MoS域名列表选项，该选项包括一个或多个子选项，该子选项具有表示移动节点所属服务的子选项代码
interested in. However, a client SHOULD be prepared to accept a response from a server that includes other sub-option(s) or does not include the requested sub-option(s).
对……感兴趣。但是，客户机应准备接受来自包含其他子选项或不包含请求的子选项的服务器的响应。
When the DHCP server receives either a MoS IPv6 Address Option or a MoS Domain Name List Option in the ORO, the DHCP server MUST include the option in its response message as defined in [RFC3315].
当DHCP服务器在ORO中接收到MoS IPv6地址选项或MoS域名列表选项时，DHCP服务器必须按照[RFC3315]中的定义在其响应消息中包含该选项。
A server MAY use the sub-options in the received MoS IPv6 Address Option or MoS Domain Name List Option from the client's message to restrict its response to the client-requested sub-options. In the case when the server cannot find any Mobility Server satisfying a requested sub-option, the server SHOULD return the MoS Option with that sub-option and the length of the sub-option set to 0.
服务器可以使用客户端消息中接收的MoS IPv6地址选项或MoS域名列表选项中的子选项来限制其对客户端请求的子选项的响应。如果服务器找不到任何满足请求的子选项的移动服务器，则服务器应返回MoS选项，并将该子选项和子选项的长度设置为0。
The security considerations in [RFC2131] apply. If an adversary manages to modify the response from a DHCP server or insert its own response, an MN could be led to contact a rogue Mobility Server, possibly one that then would provide wrong information, event or command for handover.
[RFC2131]中的安全注意事项适用。如果对手设法修改来自DHCP服务器的响应或插入其自己的响应，MN可能会被引导与恶意移动服务器联系，该服务器可能会为切换提供错误的信息、事件或命令。
It is recommended to use either DHCP authentication option described in [RFC3118] where available. This will also protect the denial-of-service attacks to DHCP servers. [RFC3118] provides mechanisms for both entity authentication and message authentication.
如果可用，建议使用[RFC3118]中描述的DHCP身份验证选项。这还将保护对DHCP服务器的拒绝服务攻击。[RFC3118]提供实体身份验证和消息身份验证的机制。
In deployments where DHCP authentication is not available, lower-layer security services may be sufficient to protect DHCP messages.
在DHCP身份验证不可用的部署中，较低层安全服务可能足以保护DHCP消息。
Regarding domain name resolution, it is recommended to consider the usage of DNSSEC [RFC4033] and the aspects of DNSSEC Operational Practices [RFC4641]. Security considerations described in [RFC5679] also apply.
关于域名解析，建议考虑DNSSEC[RCF4033 ]和DNSSEC操作实践[RCF461]方面的使用。[RFC5679]中描述的安全注意事项也适用。
This document defines two new DHCPv4 options as described in Sections 2 and 3.
本文件定义了两个新的DHCPv4选项，如第2节和第3节所述。
MoS IPv4 Address Option for DHCPv4 (OPTION-IPv4_Address-MoS) 139
DHCPv4的MoS IPv4地址选项（选项-IPv4\U地址-MoS）139
MoS Domain Name List option for DHCPv4 (OPTION-IPv4_FQDN-MoS) 140
DHCPv4的MoS域名列表选项（选项-IPv4_FQDN-MoS）140
This document creates a new registry for the Sub-Option fields in the MoS DHCPv4 Address and FQDN options called the "IEEE 802.21 Service Type" (Section 2 and 3).
本文档为MoS DHCPv4地址和FQDN选项中的子选项字段创建了一个新的注册表，称为“IEEE 802.21服务类型”（第2节和第3节）。
IS 1 CS 2 ES 3
是1 CS 2 ES 3吗
The values '0' and '255' are reserved. Values '1' through '3' are allocated as above, and the rest are available for allocation. New values can be allocated via Standards Action as defined in [RFC5226].
值“0”和“255”是保留的。值“1”到“3”的分配如上所述，其余可供分配。可通过[RFC5226]中定义的标准操作分配新值。
This document also defines two DHCPv6 options as described in Sections 4 and 5.
本文件还定义了第4节和第5节所述的两个DHCPv6选项。
MoS IPv6 Address Option for DHCPv6 (OPTION-IPv6_Address-MoS) 54
DHCPv6的MoS IPv6地址选项（选项-IPv6_地址-MoS）54
MoS Domain Name List option for DHCPv6 (OPTION-IPv6_FQDN-MoS) 55
DHCPv6的MoS域名列表选项（选项-IPv6_FQDN-MoS）55
This document creates a new registry for the sub-option field in the MoS DHCPv6 Address and FQDN options called the "IEEE 802.21 IPv6 Service Type" (Sections 4 and 5).
本文档为MoS DHCPv6地址和FQDN选项中的子选项字段创建了一个新的注册表，称为“IEEE 802.21 IPv6服务类型”（第4节和第5节）。
IS 1 CS 2 ES 3
是1 CS 2 ES 3吗
The values '0' and '65535' are reserved. Values '1' through '3' are allocated as above, and the rest are available for allocation. New values can be allocated via Standards Action as defined in [RFC5226].
值“0”和“65535”是保留的。值“1”到“3”的分配如上所述，其余可供分配。可通过[RFC5226]中定义的标准操作分配新值。
The authors would like to acknowledge the following individuals for their valuable comments: Alfred Hoenes, Bernie Volz, David W. Hankins, Jari Arkko, Telemaco Melia, Ralph Droms, Ted Lemon, Vijay Devarapalli, and Yoshihiro Ohba.
作者感谢以下个人的宝贵意见：阿尔弗雷德·霍恩斯、伯尼·沃兹、大卫·W·汉金斯、贾里·阿尔科、Telemaco Melia、拉尔夫·德罗姆斯、特德·莱蒙、维杰·德瓦拉帕利和大叶吉弘。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997.
[RFC2131]Droms，R.，“动态主机配置协议”，RFC21311997年3月。
[RFC3118] Droms, R., Ed., and W. Arbaugh, Ed., "Authentication for DHCP Messages", RFC 3118, June 2001.
[RFC3118]Droms，R.，Ed.，和W.Arbaugh，Ed.，“DHCP消息的身份验证”，RFC31182001年6月。
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003.
[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）”，RFC3315，2003年7月。
[RFC3396] Lemon, T. and S. Cheshire, "Encoding Long Options in the Dynamic Host Configuration Protocol (DHCPv4)", RFC 3396, November 2002.
[RFC3396]Lemon，T.和S.Cheshire，“动态主机配置协议（DHCPv4）中的长选项编码”，RFC 3396，2002年11月。
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. Rose, "DNS Security Introduction and Requirements", RFC 4033, March 2005.
[RFC4033]Arends，R.，Austein，R.，Larson，M.，Massey，D.，和S.Rose，“DNS安全介绍和要求”，RFC 4033，2005年3月。
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
[RFC5226]Narten，T.和H.Alvestrand，“在RFCs中编写IANA注意事项部分的指南”，BCP 26，RFC 5226，2008年5月。
[RFC5677] Melia, T., Ed., Bajko, G., Das, S., Golmie, N., and JC. Zuniga, "IEEE 802.21 Mobility Services Framework Design (MSFD)", RFC 5677, December 2009.
[RFC5677]Melia，T.，Ed.，Bajko，G.，Das，S.，Golmie，N.，和JC。Zuniga，“IEEE 802.21移动服务框架设计（MSFD）”，RFC 5677，2009年12月。
[RFC5679] Bajko, G., "Locating IEEE 802.21 Mobility Services Using DNS", RFC 5679, December 2009.
[RFC5679]Bajko，G.“使用DNS定位IEEE 802.21移动服务”，RFC 5679，2009年12月。
[RFC4641] Kolkman, O. and R. Gieben, "DNSSEC Operational Practices", RFC 4641, September 2006.
[RFC4641]Kolkman，O.和R.Gieben，“DNSSEC运营实践”，RFC 46412006年9月。
[IEEE802.21] "IEEE Standard for Local and Metropolitan Area Networks - Part 21: Media Independent Handover Services", IEEE LAN/MAN Std 802.21-2008, January 2009, http://www.ieee802.org/21/private/Published%20Spec/ 802.21-2008.pdf (access to the document requires membership).
[IEEE802.21]“局域网和城域网IEEE标准-第21部分：媒体独立切换服务”，IEEE LAN/MAN Std 802.21-2008，2009年1月，http://www.ieee802.org/21/private/Published%20Spec/ 802.21-2008.pdf（访问该文件需要会员资格）。
Authors' Addresses
作者地址
Gabor Bajko Nokia EMail: gabor.bajko@nokia.com
Gabor Bajko诺基亚电子邮件：Gabor。bajko@nokia.com
Subir Das Telcordia Technologies Inc. EMail: subir@research.telcordia.com
Subir Das Telcordia Technologies Inc.电子邮件：subir@research.telcordia.com