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Autonomous-System-Wide Unique BGP Identifier for BGP-4
draft-ietf-idr-bgp-identifier-14

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 6286.
Authors Enke Chen , Jenny Yuan
Last updated 2015-10-14 (Latest revision 2011-05-04)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
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Stream WG state WG Document
Document shepherd (None)
IESG IESG state Became RFC 6286 (Proposed Standard)
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Consensus boilerplate Unknown
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Responsible AD Stewart Bryant
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draft-ietf-idr-bgp-identifier-14
Network Working Group                                           E. Chen
Internet Draft                                                  J. Yuan
Intended Status: Standards Track                          Cisco Systems
Updates: RFC 4271                                           May 4, 2011
Expiration Date: November 5, 2011

                AS-wide Unique BGP Identifier for BGP-4

                  draft-ietf-idr-bgp-identifier-14.txt

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on November 5, 2011.

Copyright Notice

   Copyright (c) 2011 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
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   the Trust Legal Provisions and are provided without warranty as

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Internet Draft    draft-ietf-idr-bgp-identifier-14.txt          May 2011

   described in the Simplified BSD License.

Abstract

   To accommodate situations where the current requirements for the BGP
   Identifier are not met, this document relaxes the definition of the
   BGP Identifier to be a 4-octet unsigned, non-zero integer, and
   relaxes the "uniqueness" requirement so that only AS-wide uniqueness
   of the BGP Identifiers is required. These revisions to the base BGP
   specification do not introduce any backward compatibility issue.

1. Introduction

   Currently the BGP Identifier of a BGP speaker is specified as a valid
   IPv4 host address assigned to the BGP speaker [RFC4271].  In
   addition, the deployed BGP code requires that two BGP speakers be of
   distinct BGP Identifiers in order to establish a BGP connection.

   To accommodate situations where the current requirements for the BGP
   Identifier are not met (such as in the case of an IPv6-only network),
   this document relaxes the definition of the BGP Identifier to be a
   4-octet unsigned, non-zero integer, and relaxes the "uniqueness"
   requirement so that only AS-wide uniqueness of the BGP Identifiers is
   required. These revisions to the base BGP specification do not
   introduce any backward compatibility issue.

2. Protocol Revisions

   The revisions to the base BGP specification [RFC4271] include the
   definition of the BGP Identifier and procedures for a BGP speaker
   that supports the AS-wide Unique BGP Identifier.

2.1. Definition of the BGP Identifier

   For a BGP speaker that supports the AS-wide Unique BGP Identifier,
   the BGP Identifier is specified as the following:

     The BGP Identifier is a 4-octet unsigned, non-zero integer that
     should be unique within an AS. The value of the BGP Identifier for
     a BGP speaker is determined on startup and is the same for every
     local interface and every BGP peer.

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Internet Draft    draft-ietf-idr-bgp-identifier-14.txt          May 2011

2.2. Open Message Error Handling

   For a BGP speaker that supports the AS-wide Unique BGP Identifier,
   the OPEN message error handling related to the BGP Identifier is
   modified as follows:

     If the BGP Identifier field of the OPEN message is zero, or if
     it is the same as the BGP Identifier of the local BGP speaker
     and the message is from an internal peer, then the Error Subcode
     is set to "Bad BGP Identifier".

2.3. Connection Collision Resolution

   For a BGP speaker that supports the AS-wide Unique BGP Identifier,
   the procedures for connection collision resolution are extended as
   follows to deal with the case in which the two BGP speakers share the
   same BGP Identifier (thus it is only applicable to an external peer):

     If the BGP Identifiers of the peers involved in the connection
     collision are identical, then the connection initiated by the BGP
     speaker with the larger AS number is preserved.

   This extension covers cases in which the four-octet AS numbers are
   involved [RFC4893].

3. Remarks

   It is noted that a BGP Identifier allocated based on [RFC4271] fits
   the revised definition.

   In case of BGP Confederation, the whole confederation is considered
   as one AS for the purpose of supporting the AS-wide Unique BGP
   Identifier.

   A BGP speaker that supports the AS-wide Unique BGP Identifier can not
   share a BGP Identifier with its external neighbor until the remote
   BGP speaker is upgraded with software that supports the specified
   revisions.

   In addition to the OPEN message, the BGP Identifier is currently also
   used in the following areas:

     o In the AGGREAGTOR attribute of a route where the combination of
       a BGP Identifier and an AS number uniquely identifies the BGP
       speaker that performs the route aggregation.

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Internet Draft    draft-ietf-idr-bgp-identifier-14.txt          May 2011

     o In the Route Reflection within an AS, where only the BGP
       Identifier of an internal neighbor may be propagated in the
       route reflection related attributes.

     o In the route selection, where the BGP Identifier is not used
       in comparing a route from an internal neighbor and a route from
       an external neighbor. In addition, routes from BGP speakers with
       identical BGP Identifiers have been dealt with (e.g., parallel
       BGP sessions between two BGP speakers).

   Therefore it is concluded that the revisions specified in this
   document do not introduce any backward compatibility issue with the
   current usage of the BGP Identifier.

4. Security Considerations

   This extension to BGP does not introduce new security considerations.
   BGP security considerations are discussed in [RFC4271].

5. IANA Considerations

   This document has no actions for IANA.

6. Acknowledgments

   The authors would like to thank members of the IDR Working Group for
   discussions on the "IPv6-only Network" related issues that inspired
   this document.

7. Normative References

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

   [RFC4893] Vohra, Q., and E. Chen, "BGP Support for Four-octet AS
   Number Space", RFC 4893, May 2007.

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Internet Draft    draft-ietf-idr-bgp-identifier-14.txt          May 2011

8. Authors' Addresses

   Enke Chen
   Cisco Systems, Inc.
   170 W. Tasman Dr.
   San Jose, CA 95134

   EMail: enkechen@cisco.com

   Jenny Yuan
   Cisco Systems, Inc.
   170 W. Tasman Dr.
   San Jose, CA 95134

   EMail: jenny@cisco.com

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