Internet Engineering Task Force (IETF) M. Boucadair
Request for Comments: 8115 Orange
Category: Standards Track J. Qin
ISSN: 2070-1721 Cisco
T. Tsou
Philips Lighting
X. Deng
The University of New South Wales
March 2017
Internet Engineering Task Force (IETF) M. Boucadair
Request for Comments: 8115 Orange
Category: Standards Track J. Qin
ISSN: 2070-1721 Cisco
T. Tsou
Philips Lighting
X. Deng
The University of New South Wales
March 2017
DHCPv6 Option for IPv4-Embedded Multicast and Unicast IPv6 Prefixes
用于IPv4嵌入式多播和单播IPv6前缀的DHCPv6选项
Abstract
摘要
This document defines a Dynamic Host Configuration Protocol version 6 (DHCPv6) Option for multicast IPv4 service continuity solutions, which is used to carry the IPv6 prefixes to be used to build unicast and multicast IPv4-embedded IPv6 addresses.
本文档为多播IPv4服务连续性解决方案定义了一个动态主机配置协议版本6（DHCPv6）选项，该选项用于携带用于构建单播和多播IPv4嵌入式IPv6地址的IPv6前缀。
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 http://www.rfc-editor.org/info/rfc8115.
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http://www.rfc-editor.org/info/rfc8115.
Copyright Notice
版权公告
Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2017 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 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(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许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. OPTION_V6_PREFIX64 DHCPv6 Option . . . . . . . . . . . . . . 3
4. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Appendix A. Configuration Recommendations for DHCP Servers . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. OPTION_V6_PREFIX64 DHCPv6 Option . . . . . . . . . . . . . . 3
4. DHCPv6 Client Behavior . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Appendix A. Configuration Recommendations for DHCP Servers . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
Several solutions (e.g., [RFC8114]) are proposed for the delivery of multicast services in the context of transition to IPv6. Even if these solutions may have different applicable use cases, they all use specific IPv6 addresses that embed IPv4 addresses, for both multicast group and source addresses.
提出了几种解决方案（例如，[RFC8114]），用于在过渡到IPv6的情况下提供多播服务。即使这些解决方案可能有不同的适用用例，它们都使用嵌入IPv4地址的特定IPv6地址，用于多播组和源地址。
This document defines a DHCPv6 option [RFC3315] that carries the IPv6 prefixes to be used for constructing these IPv4-embedded IPv6 addresses.
本文档定义了一个DHCPv6选项[RFC3315]，该选项带有用于构建这些IPv4嵌入IPv6地址的IPv6前缀。
In particular, this option can be used in the context of Dual-Stack Lite (DS-Lite) [RFC6333], Stateless Address plus Port (A+P) [RFC6346], and other IPv4-IPv6 transition techniques.
特别是，此选项可以在双栈Lite（DS Lite）[RFC6333]、无状态地址加端口（A+P）[RFC6346]和其他IPv4-IPv6转换技术的上下文中使用。
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 RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
This document makes use of the following terms:
本文件使用了以下术语：
IPv4-embedded IPv6 address: an IPv6 address that embeds a 32-bit-encoded IPv4 address [RFC6052]. An IPv4-embedded IPv6 address can be a unicast or a multicast address.
IPv4嵌入IPv6地址：嵌入32位编码IPv4地址的IPv6地址[RFC6052]。IPv4嵌入IPv6地址可以是单播或多播地址。
Prefix64: an IPv6 prefix used for synthesizing IPv4-embedded IPv6 addresses. A Prefix64 can be unicast or multicast.
Prefix64：用于合成IPv4嵌入IPv6地址的IPv6前缀。Prefix64可以是单播或多播。
Note: "64" is used as an abbreviation for IPv6-IPv4 interconnection.
注：“64”用作IPv6-IPv4互连的缩写。
ASM_mPrefix64: a multicast Prefix64 that belongs to the Any-Source Multicast (ASM) range.
ASM\u mPrefix64：属于任意源多播（ASM）范围的多播前缀64。
SSM_mPrefix64: a multicast Prefix64 which belongs to the Source-Specific Multicast (SSM) [RFC4607] range.
SSM_mPrefix64：属于源特定多播（SSM）[RFC4607]范围的多播前缀x64。
uPrefix64: a unicast Prefix64 for building the IPv4-embedded IPv6 addresses of multicast sources in SSM mode.
uPrefix64：用于在SSM模式下构建多播源的IPv4嵌入式IPv6地址的单播前缀64。
OPTION_V6_PREFIX64 (Figure 1) conveys the IPv6 prefix(es) to be used (e.g., by an mB4 [RFC8114]) to synthesize IPv4-embedded IPv6 addresses.
选项_V6_PREFIX64（图1）传递用于合成IPv4嵌入IPv6地址的IPv6前缀（例如，由mB4[RFC8114]）。
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_V6_PREFIX64 | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| asm-length | |
+-+-+-+-+-+-+-+-+ :
: ASM_mPrefix64 :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ssm-length | |
+-+-+-+-+-+-+-+-+ :
: SSM_mPrefix64 :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unicast-length| |
+-+-+-+-+-+-+-+-+ :
: uPrefix64 (Variable) :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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_V6_PREFIX64 | option-length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| asm-length | |
+-+-+-+-+-+-+-+-+ :
: ASM_mPrefix64 :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ssm-length | |
+-+-+-+-+-+-+-+-+ :
: SSM_mPrefix64 :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unicast-length| |
+-+-+-+-+-+-+-+-+ :
: uPrefix64 (Variable) :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Option Format for OPTION_V6_PREFIX64
图1:Option_V6_PREFIX64的选项格式
The fields of the option shown in Figure 1 are as follows:
图1所示的选项字段如下所示：
option-code: OPTION_V6_PREFIX64 (see Section 6).
选项代码：选项6前缀64（参见第6节）。
option-length: length of the option, in octets.
选项长度：选项的长度，以八位字节为单位。
asm-length: the prefix length for the ASM IPv4-embedded prefix, as an 8-bit unsigned integer. This field represents the number of valid leading bits in the prefix. This field MUST be set to 96.
asm长度：asm IPv4嵌入前缀的前缀长度，为8位无符号整数。此字段表示前缀中的有效前导位数。此字段必须设置为96。
ASM_mPrefix64: this field identifies the IPv6 multicast prefix to be used to synthesize the IPv4-embedded IPv6 addresses of the multicast groups in the ASM mode. The conveyed multicast IPv6 prefix MUST belong to the ASM range.
ASM_mPrefix64:此字段标识用于在ASM模式下合成多播组的IPv4嵌入IPv6地址的IPv6多播前缀。传送的多播IPv6前缀必须属于ASM范围。
ssm-length: the prefix length for the SSM IPv4-embedded prefix, as an 8-bit unsigned integer. This field represents the number of valid leading bits in the prefix. This field MUST be set to 96.
ssm长度：ssm IPv4嵌入前缀的前缀长度，为8位无符号整数。此字段表示前缀中的有效前导位数。此字段必须设置为96。
SSM_mPrefix64: this field identifies the IPv6 multicast prefix to be used to synthesize the IPv4-embedded IPv6 addresses of the multicast groups in SSM mode. The conveyed multicast IPv6 prefix MUST belong to the SSM range.
SSM_mPrefix64：此字段标识用于在SSM模式下合成多播组的IPv4嵌入IPv6地址的IPv6多播前缀。传送的多播IPv6前缀必须属于SSM范围。
unicast-length: the prefix length for the IPv6 unicast prefix to be used to synthesize the IPv4-embedded IPv6 addresses of the multicast sources, as an 8-bit unsigned integer. As specified in [RFC6052], the unicast-length MUST be one of 32, 40, 48, 56, 64, or 96. This field represents the number of valid leading bits in the prefix.
单播长度：用于合成多播源的IPv4嵌入IPv6地址的IPv6单播前缀的前缀长度，为8位无符号整数。按照[RFC6052]中的规定，单播长度必须是32、40、48、56、64或96中的一个。此字段表示前缀中的有效前导位数。
uPrefix64: this field identifies the IPv6 unicast prefix to be used in SSM mode for constructing the IPv4-embedded IPv6 addresses representing the IPv4 multicast sources in the IPv6 domain. uPrefix64 may also be used to extract the IPv4 address from the received multicast data flows. It is a variable-size field with the length of the field defined by the unicast-length field and is rounded up to the nearest octet boundary. In this case, any additional padding bits must be zeroed. The address mapping MUST follow the guidelines documented in [RFC6052].
uPrefix64:此字段标识在SSM模式下用于构造表示IPv6域中IPv4多播源的IPv4嵌入式IPv6地址的IPv6单播前缀。uPrefix64还可用于从接收的多播数据流中提取IPv4地址。它是一个可变大小的字段，字段长度由单播长度字段定义，并向上舍入到最近的八位字节边界。在这种情况下，任何额外的填充位都必须归零。地址映射必须遵循[RFC6052]中记录的指南。
Multiple instances of OPTION_V6_PREFIX64 may be returned to a DHCPv6 client. Configuration recommendations for DHCP servers are listed in Appendix A.
选项_V6_PREFIX64的多个实例可能会返回给DHCPv6客户端。附录A中列出了DHCP服务器的配置建议。
Note that it was tempting to define three distinct DHCPv6 options, but that approach was not adopted because it has a side effect: the specification of a DHCPv6 option that could be used to discover unicast Prefix64s in environments where multicast is not enabled. Such a side effect conflicts with the recommendation to support the Well-Known DNS Name heuristic discovery-based method for unicast-only environments (Section 6 of [RFC7051]).
请注意，定义三个不同的DHCPv6选项很有诱惑力，但没有采用这种方法，因为它有一个副作用：DHCPv6选项的规范，可用于在未启用多播的环境中发现单播前缀x64。这种副作用与支持用于仅单播环境的众所周知的DNS名称启发式发现方法的建议（RFC7051第6节）相冲突。
To retrieve the IPv6 prefixes that will be used to synthesize unicast and multicast IPv4-embedded IPv6 addresses, the DHCPv6 client MUST include the OPTION_V6_PREFIX64 code in its OPTION_ORO. If the DHCPv6 client receives more than one OPTION_V6_PREFIX64 option from the DHCPv6 server:
要检索将用于合成单播和多播IPv4嵌入IPv6地址的IPv6前缀，DHCPv6客户端必须在其选项\u ORO中包含选项\u V6\u PREFIX64代码。如果DHCPv6客户端从DHCPv6服务器接收到多个选项\u V6\u PREFIX64选项：
o If each enclosed IPv6 multicast prefix has a distinct scope [RFC7346], the client MUST select the appropriate IPv6 multicast prefix whose scope matches the IPv4 multicast address used to synthesize an IPv4-embedded IPv6 multicast address.
o 如果每个封闭的IPv6多播前缀具有不同的作用域[RFC7346]，则客户端必须选择适当的IPv6多播前缀，其作用域与用于合成IPv4嵌入IPv6多播地址的IPv4多播地址匹配。
o If at least two of the received options convey IPv6 multicast prefixes that have the same scope, the said options MUST be discarded.
o 如果至少两个接收到的选项传递具有相同作用域的IPv6多播前缀，则必须丢弃所述选项。
If asm-length, ssm-length and unicast-length fields are all set to 0, the DHCPv6 client MUST behave as if OPTION_V6_PREFIX64 had not been received in the response received from the DHCPv6 server.
如果asm length、ssm length和unicast length字段都设置为0，则DHCPv6客户端的行为必须与从DHCPv6服务器接收的响应中未接收到选项_V6_PREFIX64一样。
If the asm-length field is non-null, the IPv6 prefix identified by ASM_mPrefix64 is used to synthesize IPv4-embedded IPv6 multicast addresses in the ASM range. This is achieved by concatenating the ASM_mPrefix64 and the IPv4 multicast address; the IPv4 multicast address is inserted in the last 32 bits of the IPv4-embedded IPv6 multicast address.
如果asm长度字段非空，则asm_mPrefix64标识的IPv6前缀将用于合成asm范围内的IPv4嵌入式IPv6多播地址。这是通过连接ASM_mPrefix64和IPv4多播地址来实现的；IPv4多播地址插入IPv4嵌入式IPv6多播地址的最后32位。
If the ssm-length field is non-null, the IPv6 prefix identified by SSM_mPrefix64 is used to synthesize IPv4-embedded IPv6 multicast addresses in the SSM range. This is achieved by concatenating the SSM_mPrefix64 and the IPv4 multicast address; the IPv4 multicast address is inserted in the last 32 bits of the IPv4-embedded IPv6 multicast address.
如果ssm长度字段非空，则ssm_mPrefix64标识的IPv6前缀用于合成ssm范围内的IPv4嵌入IPv6多播地址。这是通过连接SSM_mPrefix64和IPv4多播地址来实现的；IPv4多播地址插入IPv4嵌入式IPv6多播地址的最后32位。
If the unicast-length field is non-null, the IPv6 prefix identified by uPrefix64 is used to synthesize IPv4-embedded IPv6 unicast addresses as specified in [RFC6052].
如果单播长度字段非空，则uPrefix64标识的IPv6前缀用于合成[RFC6052]中指定的IPv4嵌入IPv6单播地址。
The security considerations documented in [RFC3315] and [RFC6052] are to be considered.
应考虑[RFC3315]和[RFC6052]中记录的安全注意事项。
IANA has assigned the following option code in the "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)" registry <http://www.iana.org/assignments/dhcpv6-parameters>:
IANA已在“IPv6动态主机配置协议（DHCPv6）”注册表中分配了以下选项代码<http://www.iana.org/assignments/dhcpv6-parameters>:
Option Name Value
------------------ -----
OPTION_V6_PREFIX64 113
Option Name Value
------------------ -----
OPTION_V6_PREFIX64 113
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <http://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<http://www.rfc-editor.org/info/rfc2119>.
[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, <http://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<http://www.rfc-editor.org/info/rfc3315>.
[RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for IP", RFC 4607, DOI 10.17487/RFC4607, August 2006, <http://www.rfc-editor.org/info/rfc4607>.
[RFC4607]Holbrook，H.和B.Cain，“IP的源特定多播”，RFC 4607，DOI 10.17487/RFC4607，2006年8月<http://www.rfc-editor.org/info/rfc4607>.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, DOI 10.17487/RFC6052, October 2010, <http://www.rfc-editor.org/info/rfc6052>.
[RFC6052]Bao，C.，Huitema，C.，Bagnulo，M.，Boucadair，M.，和X.Li，“IPv4/IPv6转换器的IPv6寻址”，RFC 6052，DOI 10.17487/RFC6052，2010年10月<http://www.rfc-editor.org/info/rfc6052>.
[RFC2365] Meyer, D., "Administratively Scoped IP Multicast", BCP 23, RFC 2365, DOI 10.17487/RFC2365, July 1998, <http://www.rfc-editor.org/info/rfc2365>.
[RFC2365]Meyer，D.，“管理范围的IP多播”，BCP 23，RFC 2365，DOI 10.17487/RFC2365，1998年7月<http://www.rfc-editor.org/info/rfc2365>.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-Stack Lite Broadband Deployments Following IPv4 Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, <http://www.rfc-editor.org/info/rfc6333>.
[RFC6333]Durand，A.，Droms，R.，Woodyatt，J.，和Y.Lee，“IPv4耗尽后的双栈Lite宽带部署”，RFC 6333，DOI 10.17487/RFC6333，2011年8月<http://www.rfc-editor.org/info/rfc6333>.
[RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to the IPv4 Address Shortage", RFC 6346, DOI 10.17487/RFC6346, August 2011, <http://www.rfc-editor.org/info/rfc6346>.
[RFC6346]Bush，R.，Ed.，“IPv4地址短缺的地址加端口（A+P）方法”，RFC 6346，DOI 10.17487/RFC6346，2011年8月<http://www.rfc-editor.org/info/rfc6346>.
[RFC7051] Korhonen, J., Ed. and T. Savolainen, Ed., "Analysis of Solution Proposals for Hosts to Learn NAT64 Prefix", RFC 7051, DOI 10.17487/RFC7051, November 2013, <http://www.rfc-editor.org/info/rfc7051>.
[RFC7051]Korhonen，J.，Ed.和T.Savolainen，Ed.，“主机学习NAT64前缀的解决方案分析”，RFC 7051，DOI 10.17487/RFC7051，2013年11月<http://www.rfc-editor.org/info/rfc7051>.
[RFC7346] Droms, R., "IPv6 Multicast Address Scopes", RFC 7346, DOI 10.17487/RFC7346, August 2014, <http://www.rfc-editor.org/info/rfc7346>.
[RFC7346]Droms，R.，“IPv6多播地址范围”，RFC 7346，DOI 10.17487/RFC7346，2014年8月<http://www.rfc-editor.org/info/rfc7346>.
[RFC8114] Boucadair, M., Qin, C., Jacquenet, C., Lee, Y., and Q. Wang, "Delivery of IPv4 Multicast Services to IPv4 Clients over an IPv6 Multicast Network", RFC 8114, DOI 10.17487/RFC8114, March 2017, <http://www.rfc-editor.org/info/rfc8114>.
[RFC8114]Boucadair，M.，Qin，C.，Jacquenet，C.，Lee，Y.，和Q.Wang，“通过IPv6多播网络向IPv4客户端提供IPv4多播服务”，RFC 8114，DOI 10.17487/RFC8114，2017年3月<http://www.rfc-editor.org/info/rfc8114>.
This appendix details a set of non-normative configuration recommendations:
本附录详细说明了一组非规范性配置建议：
o DHCP servers supporting OPTION_V6_PREFIX64 must be configured with ASM_mPrefix64 or SSM_mPrefix64, and may be configured with both.
o 支持选项_V6_PREFIX64的DHCP服务器必须配置ASM_mPrefix64或SSM_mPrefix64，并且可以同时配置这两个选项。
o uPrefix64 must also be configured when SSM_mPrefix64 is provided.
o 当提供SSM_mPrefix64时，还必须配置uPrefix64。
o uPrefix64 may be configured when ASM_mPrefix64 is provided.
o 当提供ASM\U mPrefix64时，可以配置uPrefix64。
Note that uPrefix64 is not mandatory for the ASM case if, for example, a local address mapping algorithm is supported or the Well-Known Prefix (64:ff9b::/96) is used.
请注意，例如，如果支持本地地址映射算法或使用众所周知的前缀（64:ff9b:：/96），则ASM情况下uPrefix64不是必需的。
o Both ASM_mPrefix64 and SSM_mPrefix64 may be configured and therefore be returned to a requesting DHCP client in the same OPTION_V6_PREFIX64. In particular, if both SSM and ASM modes are supported, ASM_mPrefix64 and SSM_mPrefix64 prefixes must be configured. For SSM deployments, both SSM_mPrefix64 and uPrefix64 must be configured.
o ASM_mPrefix64和SSM_mPrefix64都可以配置，因此可以使用相同的选项_V6_PREFIX64返回到请求的DHCP客户端。特别是，如果支持SSM和ASM模式，则必须配置ASM_mPrefix64和SSM_mPrefix64前缀。对于SSM部署，必须同时配置SSM_mPrefix64和uPrefix64。
o When a multicast Prefix64 (ASM_mPrefix64 or SSM_mPrefix64) is configured, the length of the prefix must be /96.
o 配置多播前缀x64（ASM_mPrefix64或SSM_mPrefix64）时，前缀的长度必须为/96。
o When distinct IPv6 multicast address scopes [RFC7346] are required to preserve the scope when translating IPv4 multicast addresses (Section 8 of [RFC2365]), each scope is configured as a separate OPTION_V6_PREFIX64. How DHCP servers are configured to separate multicast Prefix64 per scope is implementation specific and not covered by this document.
o 在转换IPv4多播地址时，如果需要使用不同的IPv6多播地址作用域[RFC7346]来保留作用域（RFC2365]的第8节），则每个作用域都配置为单独的选项\u V6\u PREFIX64。如何将DHCP服务器配置为每个作用域分隔多播前缀x64是特定于实现的，本文档不涉及。
o When scope preservation is not required, only one instance of OPTION_V6_PREFIX64 is configured.
o 如果不需要范围保留，则只配置选项_V6_PREFIX64的一个实例。
Acknowledgments
致谢
Thanks to C. Jacquenet, S. Venaas, B. Volz, T. Taylor, R. Weber, R. Even, J. Sheng, T. Mrugalski, and T. Chown for their review.
感谢C.Jacquenet、S.Venaas、B.Volz、T.Taylor、R.Weber、R.Even、J.Sheng、T.Mrugalski和T.Chown的评论。
Many thanks to I. Farrer and T. Lemon for the comments.
非常感谢I.Farrer和T.Lemon的评论。
Authors' Addresses
作者地址
Mohamed Boucadair Orange Rennes 35000 France
穆罕默德·布卡代尔·奥兰治·雷恩35000法国
Email: mohamed.boucadair@orange.com
Email: mohamed.boucadair@orange.com
Jacni Qin Cisco Shanghai China
中国上海思科公司
Email: jacni@jacni.com
Email: jacni@jacni.com
Tina Tsou Philips Lighting United States of America
Tina Tsou Philips Lighting美利坚合众国
Email: tina.tsou@philips.com
Email: tina.tsou@philips.com
Xiaohong Deng The University of New South Wales Sydney NSW 2052 Australia
萧红登新南威尔士大学悉尼新南威尔士2052澳大利亚
Email: dxhbupt@gmail.com
Email: dxhbupt@gmail.com