From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc6996.txt | 227 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 227 insertions(+) create mode 100644 doc/rfc/rfc6996.txt (limited to 'doc/rfc/rfc6996.txt') diff --git a/doc/rfc/rfc6996.txt b/doc/rfc/rfc6996.txt new file mode 100644 index 0000000..e4ef413 --- /dev/null +++ b/doc/rfc/rfc6996.txt @@ -0,0 +1,227 @@ + + + + + + +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 + +Abstract + + 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. + +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. + + 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/rfc6996. + +Copyright Notice + + Copyright (c) 2013 IETF Trust and the persons identified as the + document authors. All rights reserved. + + 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. + + + + +Mitchell Best Current Practice [Page 1] + +RFC 6996 Private Use AS Reservation July 2013 + + +1. Introduction + + 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 + + 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]. + +3. Private Use ASNs + + 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 + + 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 + + + +Mitchell Best Current Practice [Page 2] + +RFC 6996 Private Use AS Reservation July 2013 + + + 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 + + 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 + + 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 + +7.1. Normative References + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, March 1997. + + [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway + Protocol 4 (BGP-4)", RFC 4271, January 2006. + + [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet + Autonomous System (AS) Number Space", RFC 6793, + December 2012. + + + + +Mitchell Best Current Practice [Page 3] + +RFC 6996 Private Use AS Reservation July 2013 + + +7.2. Informative References + + [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. + + [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", + RFC 4272, January 2006. + +8. Acknowledgements + + 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. + +Author's Address + + Jon Mitchell + Microsoft Corporation + One Microsoft Way + Redmond, WA 98052 + USA + + EMail: Jon.Mitchell@microsoft.com + + + + + + + + + + + + + + + + + + + + + + +Mitchell Best Current Practice [Page 4] + -- cgit v1.2.3