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 | RFC Internet-Draft (idr WG) | |
|---|---|---|---|
| Authors | Enke Chen , Jenny Yuan | ||
| Last updated | 2015-10-14 (Latest revision 2011-05-04) | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text htmlized pdfized bibtex | ||
| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | RFC 6286 (Proposed Standard) | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | Stewart Bryant | ||
| IESG note | John Scudder (jgs@juniper.net) is the document shepherd. | ||
| Send notices to | (None) |
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
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Chen & Yuan [Page 1]
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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