Internet Engineering Task Force (IETF) J. Heitz, Ed.
Request for Comments: 8092 Cisco
Category: Standards Track J. Snijders, Ed.
ISSN: 2070-1721 NTT
K. Patel
Arrcus
I. Bagdonas
Equinix
N. Hilliard
INEX
February 2017
Internet Engineering Task Force (IETF) J. Heitz, Ed.
Request for Comments: 8092 Cisco
Category: Standards Track J. Snijders, Ed.
ISSN: 2070-1721 NTT
K. Patel
Arrcus
I. Bagdonas
Equinix
N. Hilliard
INEX
February 2017
BGP Large Communities Attribute
大型社区属性
Abstract
摘要
This document describes the BGP Large Communities attribute, an extension to BGP-4. This attribute provides a mechanism to signal opaque information within separate namespaces to aid in routing management. The attribute is suitable for use with all Autonomous System Numbers (ASNs) including four-octet ASNs.
本文档介绍BGP大型社区属性，它是BGP-4的扩展。此属性提供了一种机制，可以在单独的名称空间中发出不透明信息的信号，以帮助进行路由管理。该属性适用于所有自治系统编号（ASN），包括四个八位组ASN。
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/rfc8092.
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/rfc8092.
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
2. Requirements Language ...........................................3
3. BGP Large Communities Attribute .................................3
4. Aggregation .....................................................4
5. Canonical Representation ........................................4
6. Error Handling ..................................................5
7. Security Considerations .........................................5
8. IANA Considerations .............................................6
9. References ......................................................6
9.1. Normative References .......................................6
9.2. Informative References .....................................6
Acknowledgments ....................................................7
Contributors .......................................................7
Authors' Addresses .................................................8
1. Introduction ....................................................2
2. Requirements Language ...........................................3
3. BGP Large Communities Attribute .................................3
4. Aggregation .....................................................4
5. Canonical Representation ........................................4
6. Error Handling ..................................................5
7. Security Considerations .........................................5
8. IANA Considerations .............................................6
9. References ......................................................6
9.1. Normative References .......................................6
9.2. Informative References .....................................6
Acknowledgments ....................................................7
Contributors .......................................................7
Authors' Addresses .................................................8
BGP [RFC4271] implementations typically support a routing policy language to control the distribution of routing information. Network operators attach BGP communities to routes to associate particular properties with these routes. These properties may include information such as the route origin location, or specification of a routing policy action to be taken, or one that has been taken, and is applied to all routes contained in a BGP Update Message where the Communities Attribute is included. Because BGP communities are optional transitive BGP attributes, BGP communities may be acted upon or otherwise used by routing policies in other Autonomous Systems (ASes) on the Internet.
BGP[RFC4271]实现通常支持路由策略语言来控制路由信息的分发。网络运营商将BGP社区连接到路由，以将特定属性与这些路由关联。这些属性可能包括诸如路由起始位置、将要采取的路由策略操作的规范或已采取的路由策略操作等信息，并应用于包含社区属性的BGP更新消息中包含的所有路由。由于BGP社区是可选的可传递BGP属性，因此BGP社区可以由Internet上其他自治系统（ASE）中的路由策略执行操作或以其他方式使用。
A BGP Communities attribute is a variable-length attribute consisting of a set of one or more four-octet values, each of which specify a community [RFC1997]. Common use of the individual values of this attribute type split this single 32-bit value into two 16-bit values. The most significant word is interpreted as an Autonomous System Number (ASN), and the least significant word is a locally defined value whose meaning is assigned by the operator of the AS in the most significant word.
BGP Communities属性是一个可变长度属性，由一组一个或多个八位组值组成，每个八位组值指定一个社区[RFC1997]。此属性类型的单个值的常用用法将此单个32位值拆分为两个16位值。最重要的单词被解释为自治系统编号（ASN），最不重要的单词是本地定义的值，其含义由最重要单词中的as运算符指定。
Since the adoption of four-octet ASNs [RFC6793], the BGP Communities attribute can no longer accommodate the above encoding, as a two-octet word cannot fit a four-octet ASN. The BGP Extended Communities attribute [RFC4360] is also unsuitable. The six-octet length of the Extended Community value precludes the common operational practice of encoding four-octet ASNs in both the Global Administrator and the Local Administrator sub-fields.
由于采用了四个八位字节的ASN[RFC6793]，BGP Communities属性无法再适应上述编码，因为两个八位字节的字不能适应四个八位字节的ASN。BGP扩展社区属性[RFC4360]也不适用。扩展社区值的六个八位字节长度排除了在全局管理员和本地管理员子字段中编码四个八位字节ASN的常见操作实践。
To address these shortcomings, this document defines a BGP Large Communities attribute encoded as an unordered set of one or more twelve-octet values, each consisting of a four-octet Global Administrator field and two four-octet operator-defined fields, each of which can be used to denote properties or actions significant to the operator of the AS assigning the values.
为了解决这些缺点，本文档定义了一个BGP大型社区属性，该属性编码为一个由一个或多个十二个八位字节值组成的无序集，每个八位字节值由一个四个八位字节全局管理员字段和两个四个八位字节运算符定义的字段组成，其中每一个都可以用来表示属性或操作，这些属性或操作对于分配值的操作人员来说非常重要。
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。
This document defines the BGP Large Communities attribute as an optional transitive path attribute of variable length. All routes with the BGP Large Communities attribute belong to the communities specified in the attribute.
本文档将BGP大型社区属性定义为可变长度的可选传递路径属性。具有BGP大型社区属性的所有路由都属于该属性中指定的社区。
Each BGP Large Community value is encoded as a 12-octet quantity, as follows:
每个BGP大团体值编码为12个八位组，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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Global Administrator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Data Part 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Data Part 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Global Administrator |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Data Part 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Data Part 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Global Administrator: A four-octet namespace identifier.
全局管理员：四个八位组的名称空间标识符。
Local Data Part 1: A four-octet operator-defined value.
本地数据第1部分：四个八位运算符定义的值。
Local Data Part 2: A four-octet operator-defined value.
本地数据第2部分：四个八位运算符定义的值。
The Global Administrator field is intended to allow different ASes to define BGP Large Communities without collision. This field SHOULD be an ASN, in which case the Local Data Parts are to be interpreted as defined by the owner of the ASN. The use of Reserved ASNs (0 [RFC7607], 65535 and 4294967295 [RFC7300]) is NOT RECOMMENDED.
“全局管理员”字段旨在允许不同的ASE定义BGP大型社区而不发生冲突。此字段应为ASN，在这种情况下，本地数据部分将按照ASN所有者的定义进行解释。不建议使用保留的ASN（0[RFC7607]、65535和4294967295[RFC7300]）。
There is no significance to the order in which twelve-octet Large Community Attribute values are encoded in a Large Communities attribute, A BGP speaker can transmit them in any order.
在一个大型社区属性中编码12个八位组大型社区属性值的顺序没有意义，BGP说话者可以以任何顺序传输它们。
Duplicate BGP Large Community values MUST NOT be transmitted. A receiving speaker MUST silently remove redundant BGP Large Community values from a BGP Large Community attribute.
不得传输重复的BGP大型社区值。接收扬声器必须以静默方式从BGP大型社区属性中删除冗余的BGP大型社区值。
If a range of routes is aggregated, then the resulting aggregate should have a BGP Large Communities attribute that contains all of the BGP Large Communities attributes from all of the aggregated routes.
如果聚合了一系列路由，则生成的聚合应具有BGP大型社区属性，该属性包含所有聚合路由的所有BGP大型社区属性。
The canonical representation of BGP Large Communities is three separate unsigned integers in decimal notation in the following order: Global Administrator, Local Data 1, Local Data 2. Numbers MUST NOT contain leading zeros; a zero value MUST be represented with a single zero. Each number is separated from the next by a single colon. For example: 64496:4294967295:2, 64496:0:0.
BGP大型社区的规范表示是三个单独的无符号整数，以十进制表示，顺序如下：全局管理员、本地数据1、本地数据2。数字不能包含前导零；零值必须用单个零表示。每个数字之间用一个冒号分隔。例如：64496:4294967295:264496:0:0。
BGP Large Communities SHOULD be represented in the canonical representation.
BGP大型社区应在规范表示中表示。
The error handling of BGP Large Communities is as follows:
BGP大型社区的错误处理如下：
o A BGP Large Communities attribute SHALL be considered malformed if the length of the BGP Large Communities Attribute value, expressed in octets, is not a non-zero multiple of 12.
o 如果BGP大型社区属性值的长度（以八位字节表示）不是12的非零倍数，则BGP大型社区属性应被视为格式不正确。
o A BGP Large Communities attribute SHALL NOT be considered malformed due to presence of duplicate Large Community values.
o 由于存在重复的大型社区值，BGP大型社区属性不应被视为格式错误。
o A BGP UPDATE message with a malformed BGP Large Communities attribute SHALL be handled using the approach of "treat-as-withdraw" as described in Section 2 of [RFC7606].
o 具有格式错误的BGP大型社区属性的BGP更新消息应使用[RFC7606]第2节所述的“视为撤回”方法进行处理。
The BGP Large Communities Global Administrator field may contain any value, and a BGP Large Communities attribute MUST NOT be considered malformed if the Global Administrator field contains an unallocated, unassigned, or reserved ASN.
BGP大型社区全局管理员字段可以包含任何值，如果全局管理员字段包含未分配、未分配或保留的ASN，则BGP大型社区属性不得被视为格式不正确。
This document does not change any underlying security issues associated with any other BGP Communities mechanism. Specifically, an AS relying on the BGP Large Communities attribute carried in BGP must have trust in every other AS in the path, as any intermediate AS in the path may have added, deleted, or altered the BGP Large Communities attribute. Specifying the mechanism to provide such trust is beyond the scope of this document.
本文档不会更改与任何其他BGP社区机制相关的任何潜在安全问题。具体而言，依赖于BGP中携带的BGP大型社区属性的AS必须信任路径中的其他AS，因为路径中的任何中间AS可能已添加、删除或更改BGP大型社区属性。指定提供此类信任的机制超出了本文档的范围。
BGP Large Communities do not protect the integrity of each community value. Operators should be aware that it is possible for a BGP speaker to alter BGP Large Community Attribute values in a BGP Update Message. Protecting the integrity of the transitive handling of BGP Large Community attributes in a manner consistent with the intent of expressed BGP routing policies falls within the broader scope of securing BGP, and is not specifically addressed here.
BGP大型社区不保护每个社区价值的完整性。操作员应注意，BGP扬声器可能会在BGP更新消息中更改BGP大型社区属性值。以符合明确的BGP路由策略意图的方式保护BGP大型社区属性的可传递处理的完整性属于保护BGP的更广泛范围，此处未具体说明。
Network administrators should note the recommendations in Section 11 of "BGP Operations and Security" [RFC7454].
网络管理员应注意“BGP操作和安全”[RFC7454]第11节中的建议。
IANA has assigned the value 32 (LARGE_COMMUNITY) in the "BGP Path Attributes" subregistry under the "Border Gateway Protocol (BGP) Parameters" registry.
IANA已在“边界网关协议（BGP）参数”注册表下的“BGP路径属性”子区域中分配了值32（大型社区）。
[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>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006, <http://www.rfc-editor.org/info/rfc4271>.
[RFC4271]Rekhter，Y.，Ed.，Li，T.，Ed.，和S.Hares，Ed.，“边境网关协议4（BGP-4）”，RFC 4271，DOI 10.17487/RFC4271，2006年1月<http://www.rfc-editor.org/info/rfc4271>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K. Patel, "Revised Error Handling for BGP UPDATE Messages", RFC 7606, DOI 10.17487/RFC7606, August 2015, <http://www.rfc-editor.org/info/rfc7606>.
[RFC7606]Chen，E.，Ed.，Scudder，J.，Ed.，Mohapatra，P.，和K.Patel，“BGP更新消息的修订错误处理”，RFC 7606，DOI 10.17487/RFC7606，2015年8月<http://www.rfc-editor.org/info/rfc7606>.
[RFC1997] Chandra, R., Traina, P., and T. Li, "BGP Communities Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996, <http://www.rfc-editor.org/info/rfc1997>.
[RFC1997]Chandra，R.，Traina，P.，和T.Li，“BGP社区属性”，RFC 1997，DOI 10.17487/RFC1997，1996年8月<http://www.rfc-editor.org/info/rfc1997>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended Communities Attribute", RFC 4360, DOI 10.17487/RFC4360, February 2006, <http://www.rfc-editor.org/info/rfc4360>.
[RFC4360]Sangli，S.，Tappan，D.和Y.Rekhter，“BGP扩展社区属性”，RFC 4360，DOI 10.17487/RFC4360，2006年2月<http://www.rfc-editor.org/info/rfc4360>.
[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet Autonomous System (AS) Number Space", RFC 6793, DOI 10.17487/RFC6793, December 2012, <http://www.rfc-editor.org/info/rfc6793>.
[RFC6793]Vohra，Q.和E.Chen，“BGP对四个八位组自治系统（AS）数字空间的支持”，RFC 6793，DOI 10.17487/RFC6793，2012年12月<http://www.rfc-editor.org/info/rfc6793>.
[RFC7300] Haas, J. and J. Mitchell, "Reservation of Last Autonomous System (AS) Numbers", BCP 6, RFC 7300, DOI 10.17487/RFC7300, July 2014, <http://www.rfc-editor.org/info/rfc7300>.
[RFC7300]Haas，J.和J.Mitchell，“保留最后一个自治系统（AS）编号”，BCP 6，RFC 7300，DOI 10.17487/RFC7300，2014年7月<http://www.rfc-editor.org/info/rfc7300>.
[RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP Operations and Security", BCP 194, RFC 7454, DOI 10.17487/RFC7454, February 2015, <http://www.rfc-editor.org/info/rfc7454>.
[RFC7454]Durand，J.，Pepelnjak，I.，和G.Doering，“BGP运营和安全”，BCP 194，RFC 7454，DOI 10.17487/RFC7454，2015年2月<http://www.rfc-editor.org/info/rfc7454>.
[RFC7607] Kumari, W., Bush, R., Schiller, H., and K. Patel, "Codification of AS 0 Processing", RFC 7607, DOI 10.17487/RFC7607, August 2015, <http://www.rfc-editor.org/info/rfc7607>.
[RFC7607]Kumari，W.，Bush，R.，Schiller，H.，和K.Patel，“AS 0处理的编目”，RFC 7607，DOI 10.17487/RFC7607，2015年8月<http://www.rfc-editor.org/info/rfc7607>.
Acknowledgments
致谢
The authors would like to thank Ruediger Volk, Russ White, Acee Lindem, Shyam Sethuram, Jared Mauch, Joel M. Halpern, Jeffrey Haas, Gunter van de Velde, Marco Marzetti, Eduardo Ascenco Reis, Mark Schouten, Paul Hoogsteder, Martijn Schmidt, Greg Hankins, Bertrand Duvivier, Barry O'Donovan, Grzegorz Janoszka, Linda Dunbar, Marco Davids, Gaurab Raj Upadhaya, Jeff Tantsura, Teun Vink, Adam Davenport, Theodore Baschak, Pier Carlo Chiodi, Nabeel Cocker, Ian Dickinson, Jan Baggen, Duncan Lockwood, David Farmer, Randy Bush, Wim Henderickx, Stefan Plug, Kay Rechthien, Rob Shakir, Warren Kumari, Gert Doering, Thomas King, Mikael Abrahamsson, Wesley Steehouwer, Sander Steffann, Brad Dreisbach, Martin Millnert, Christopher Morrow, Jay Borkenhagen, Arnold Nipper, Joe Provo, Niels Bakker, Bill Fenner, Tom Daly, Ben Maddison, Alexander Azimov, Brian Dickson, Peter van Dijk, Julian Seifert, Tom Petch, Tom Scholl, Arjen Zonneveld, Remco van Mook, Adam Chappell, Jussi Peltola, Kristian Larsson, Markus Hauschild, Richard Steenbergen, David Freedman, Richard Hartmann, Geoff Huston, Mach Chen, and Alvaro Retana for their support, insightful review, and comments.
作者要感谢Ruediger Volk、Russ White、Acee Lindem、Shyam Sethuram、Jared Mauch、Joel M.Halpern、Jeffrey Haas、Gunter van de Velde、Marco Marzetti、Eduardo Ascenco Reis、Mark Schouten、Paul Hoogsteder、Martijn Schmidt、Greg Hankins、Bertrand Duviier、Barry O'Donovan、Grzegorz Janoszka、Linda Dunbar、Marco Davids、，高拉布·拉吉·乌帕达雅、杰夫·坦特拉、特恩·文克、亚当·达文波特、西奥多·巴斯查克、皮尔·卡洛·奇奥迪、纳比尔·科克、伊恩·迪金森、扬·巴根、邓肯·洛克伍德、大卫·法默、兰迪·布什、维姆·亨德里克斯、斯特凡·普洛普、凯·雷切恩、罗布·夏吉尔、沃伦·库马里、格特·多林、托马斯·金、米凯尔·艾布拉姆松、韦斯利·斯特豪威尔、桑德·斯特凡、，布拉德·德雷斯巴赫、马丁·米尔纳特、克里斯托弗·莫罗、杰伊·博肯哈根、阿诺德·尼珀、乔·普罗沃、尼尔斯·巴克、比尔·芬纳、汤姆·戴利、本·麦迪森、亚历山大·阿齐莫夫、布赖恩·迪克森、彼得·范·迪克、朱利安·塞弗特、汤姆·佩奇、汤姆·斯科尔、阿扬·佐内维尔德、伦科·范·穆克、亚当·查佩尔、朱西·佩尔托拉、克里斯蒂安·拉尔森、马库斯·豪斯柴尔德、，Richard Steenbergen、David Freedman、Richard Hartmann、Geoff Huston、Mach Chen和Alvaro Retana感谢他们的支持、深刻的评论和评论。
Contributors
贡献者
The following people contributed significantly to the content of the document:
以下人员对本文件的内容做出了重大贡献：
John Heasley NTT Communications Email: heas@shrubbery.net
John Heasley NTT通信电子邮件：heas@shrubbery.net
Adam Simpson Nokia Email: adam.1.simpson@nokia.com
亚当·辛普森诺基亚电子邮件：Adam.1。simpson@nokia.com
Authors' Addresses
作者地址
Jakob Heitz (editor) Cisco 170 West Tasman Drive San Jose, CA 95054 United States of America
雅各布·海茨（编辑）美国加利福尼亚州圣何塞市西塔斯曼大道170号，邮编95054
Email: jheitz@cisco.com
Email: jheitz@cisco.com
Job Snijders (editor) NTT Communications Theodorus Majofskistraat 100 Amsterdam 1065 SZ The Netherlands
Job Snijders（编辑）NTT通信公司Theodorus Majofskistraat 100阿姆斯特丹1065 SZ荷兰
Email: job@ntt.net
Email: job@ntt.net
Keyur Patel Arrcus, Inc.
凯乌尔·帕特尔·阿卡斯公司。
Email: keyur@arrcus.com
Email: keyur@arrcus.com
Ignas Bagdonas Equinix 80 Cheapside London EC2V 6EE United Kingdom
Ignas Bagdonas Equinix 80 Cheapside伦敦EC2V 6EE英国
Email: ibagdona.ietf@gmail.com
Email: ibagdona.ietf@gmail.com
Nick Hilliard INEX 4027 Kingswood Road Dublin 24 Ireland
Nick Hilliard INEX 4027 Kingswood路都柏林24号爱尔兰
Email: nick@inex.ie
Email: nick@inex.ie