Internet Engineering Task Force (IETF)                       J. Mitchell
Request for Comments: 6996                         Microsoft Corporation
BCP: 6                                                         July 2013
Updates: 1930
Category: Best Current Practice
ISSN: 2070-1721
Internet Engineering Task Force (IETF)                       J. Mitchell
Request for Comments: 6996                         Microsoft Corporation
BCP: 6                                                         July 2013
Updates: 1930
Category: Best Current Practice
ISSN: 2070-1721

Autonomous System (AS) Reservation for Private Use




This document describes the reservation of Autonomous System Numbers (ASNs) that are for Private Use only, known as Private Use ASNs, and provides operational guidance on their use. This document enlarges the total space available for Private Use ASNs by documenting the reservation of a second, larger range and updates RFC 1930 by replacing Section 10 of that document.

本文件描述了仅限私人使用的自治系统编号(ASN)的保留,称为私人使用ASN,并提供了有关其使用的操作指南。本文件通过记录第二个更大范围的保留扩大了可供私人使用的ASN的总空间,并通过替换该文件的第10节更新了RFC 1930。

Status of This Memo


This memo documents an Internet Best Current Practice.


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 BCPs is available in Section 2 of RFC 5741.

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BCP的更多信息,请参见RFC 5741第2节。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.

版权所有(c)2013 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 ( 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(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。

1. Introduction
1. 介绍

The original IANA reservation of Autonomous System Numbers (ASNs) for Private Use was a block of 1023 ASNs. This was also documented by the IETF in Section 10 of [RFC1930]. Since the time that the range was reserved, the Border Gateway Protocol (BGP) [RFC4271] has seen deployment in new application domains, such as data center networks, which require a larger Private Use AS space.


Since the introduction of "BGP Support for Four-Octet Autonomous System (AS) Number Space" [RFC6793], the total size of ASN space has increased dramatically. A larger subset of the space is available to network operators to deploy in these Private Use cases. The existing range of Private Use ASNs is widely deployed, and the ability to renumber this resource in existing networks cannot be coordinated given that these ASNs, by definition, are not registered. Therefore, this RFC documents the existing Private Use ASN reservation while also introducing a second, larger range that can also be utilized.


2. Requirements Language
2. 需求语言

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。

3. Private Use ASNs
3. 自用ASN

To allow the continued growth of BGP protocol usage in new network applications that utilize Private Use ASNs, two ranges of ASNs are reserved by Section 5 of this document. The first is part of the original 16-bit Autonomous System range previously defined in [RFC1930], and the second is a larger range out of the Four-Octet AS Number Space [RFC6793].


4. Operational Considerations
4. 业务考虑

If Private Use ASNs are used and prefixes originate from these ASNs, Private Use ASNs MUST be removed from AS path attributes (including AS4_PATH if utilizing a four-octet AS number space) before being advertised to the global Internet. Operators SHOULD ensure that all External Border Gateway Protocol (EBGP) speakers support the extensions described in [RFC6793] and that implementation-specific features that recognize Private Use ASNs have been updated to recognize both ranges prior to making use of the newer, numerically higher range of Private Use ASNs in the four-octet AS number space. Some existing implementations that remove Private Use ASNs from the AS_PATH are known to not remove Private Use ASNs if the AS_PATH contains a mixture of Private Use and Non-Private Use ASNs. If such


implementations have not been updated to recognize the new range of ASNs in this document and a mix of old and new range Private Use ASNs exist in the AS4_PATH, these implementations will likely cease to remove any Private Use ASNs from either of the AS path attributes. Normal AS path filtering MAY also be used to prevent prefixes originating from Private Use ASNs from being advertised to the global Internet.


5. IANA Considerations
5. IANA考虑

IANA has reserved, for Private Use, a contiguous block of 1023 Autonomous System numbers from the "16-bit Autonomous System Numbers" registry, namely 64512 - 65534 inclusive.


IANA has also reserved, for Private Use, a contiguous block of 94,967,295 Autonomous System numbers from the "32-bit Autonomous System Numbers" registry, namely 4200000000 - 4294967294 inclusive.


These reservations have been documented in the IANA "Autonomous System (AS) Numbers" registry [IANA.AS].


6. Security Considerations
6. 安全考虑

Private Use ASNs do not raise any unique security concerns. Loss of connectivity might result from their inappropriate use, specifically outside of a single organization, since they are not globally unique. This loss of connectivity is limited to the organization using Private Use ASNs inappropriately or without reference to Section 4. General BGP security considerations are discussed in [RFC4271] and [RFC4272]. Identification of the originator of a route with a Private Use ASN in the AS path would have to be done by tracking the route back to the neighboring globally unique AS in the path or by inspecting other attributes.


7. References
7. 工具书类
7.1. Normative References
7.1. 规范性引用文件

[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。

[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.

[RFC4271]Rekhter,Y.,Li,T.,和S.Hares,“边境网关协议4(BGP-4)”,RFC 42712006年1月。

[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet Autonomous System (AS) Number Space", RFC 6793, December 2012.

[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 6793,2012年12月。

7.2. Informative References
7.2. 资料性引用

[IANA.AS] IANA, "Autonomous System (AS) Numbers", <>.


[RFC1930] Hawkinson, J. and T. Bates, "Guidelines for creation, selection, and registration of an Autonomous System (AS)", BCP 6, RFC 1930, March 1996.

[RFC1930]霍金森,J.和T.贝茨,“自主系统(AS)的创建、选择和注册指南”,BCP 6,RFC 1930,1996年3月。

[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", RFC 4272, January 2006.

[RFC4272]Murphy,S.,“BGP安全漏洞分析”,RFC 4272,2006年1月。

8. Acknowledgements
8. 致谢

The author would like to acknowledge Christopher Morrow, Jason Schiller, and John Scudder for their advice on how to pursue this change. The author would also like to thank Brian Dickson, David Farmer, Jeffrey Haas, Nick Hilliard, Joel Jaeggli, Warren Kumari, and Jeff Wheeler for their comments and suggestions.

作者要感谢Christopher Morrow、Jason Schiller和John Scudder就如何实现这一变化提出的建议。作者还要感谢Brian Dickson、David Farmer、Jeffrey Haas、Nick Hilliard、Joel Jaeggli、Warren Kumari和Jeff Wheeler的评论和建议。

Author's Address


Jon Mitchell Microsoft Corporation One Microsoft Way Redmond, WA 98052 USA

Jon Mitchell微软公司美国华盛顿州雷德蒙微软大道一号,邮编:98052