Internet DRAFT - draft-fan-idr-ipv6-bgp-id
draft-fan-idr-ipv6-bgp-id
Network Working Group P. Fan
Internet-Draft Z. Li
Intended status: Standards Track China Mobile
Expires: August 17, 2014 February 13, 2014
IPv6 BGP Identifier Capability for BGP-4
draft-fan-idr-ipv6-bgp-id-00
Abstract
To solve the problem of BGP Identifier in an IPv6-only network
without special configuration and planning considerations, this
document extends BGP to allow a BGP Identifier to be a valid IPv6
global unicast address assigned to the BGP speaker. Protocol
extension includes the definition of a BGP capability code, "IPv6 BGP
Identifier capability", to be used by a BGP speaker to indicate its
support for IPv6 address as a BGP Identifier. This document updates
RFC 4271.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
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This Internet-Draft will expire on August 17, 2014.
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Protocol Extension . . . . . . . . . . . . . . . . . . . . . 3
3. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Processing Received OPEN messages . . . . . . . . . . . . 3
3.2. Connection Collision Detection . . . . . . . . . . . . . 3
3.3. Route Selection Decision . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
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.
In an IPv6-only network, the requirements for the BGP Identifier in
[RFC4271] are not met as no IPv4 address is configured to the BGP
speaker. To accommodate this situation, [RFC6286] relaxes the
definition of the BGP Identifier to be a 4-octet, unsigned, non-zero
integer and requires AS-wide uniqueness of the BGP Identifiers.
The proposal in [RFC6286] requires that a 4-octet integer be
configured as BGP Identifier on the BGP speaker after basic IPv6
information (such as IPv6 addresses) configuration has been
completed. The 4-octec integer to be configured as BGP Identifier
has to be planned carefully in advance to guarantee uniqueness within
the AS. In a large IPv6-only AS the extra configuration and planning
work introduced by the special integers can be troublesome.
To solve the problem of BGP Identifier in an IPv6-only network
without special configuration and planning considerations, this
document extends BGP to allow a BGP Identifier to be a valid IPv6
global unicast address assigned to the BGP speaker. Protocol
extension includes the definition of a BGP capability code, "IPv6 BGP
Identifier capability", to be used by a BGP speaker to indicate its
support for IPv6 address as a BGP Identifier.
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2. Protocol Extension
A new BGP capability [RFC5492] is defined to convey the IPv6 global
unicast address to be used as the BGP Identifier. A BGP speaker uses
BGP Capabilities Advertisements in its OPEN message to advertise its
neighbors this IPv6 BGP Identifier ability. The BGP Identifier field
of the OPEN message is set to zero, indicating that actual BGP ID is
in the Capability Optional Parameter.
The Capability Length field of the IPv6 BGP Identifier Capability is
set to 16, and the Capability value field is set to one of the IPv6
global unicast addresses that have been assigned to the BGP speaker.
The BGP Identifier is also used in the AGGREGATOR attribute, so a BGP
speaker that uses IPv6 BGP Identifier Capability sets the AGGREGATOR
attribute accordingly. The BGP Identifier carried in the attribute
is encoded as a 16-octet entity.
3. Operations
3.1. Processing Received OPEN messages
A BGP speaker checks the BGP Identifier field of the OPEN message
received first. If the BGP Identifier field is not zero, then the
OPEN message is processed in the way of the message that does not
contain IPv6 BGP Identifier, and any IPv6 BGP Identifier Capability
in the Capability Optional Parameter of the message is ignored. If
the BGP Identifier field is zero, then the BGP speaker checks if any
IPv6 BGP Identifier Capability is carried in the Capability Optional
Parameter. If there is no IPv6 BGP ID Capability, or the capability
value of the IPv6 BGP ID Capability is not a valid IPv6 global
unicast address, then a Notification message is generated, with Error
Code set to 2 (OPEN Message Error) and Error subcode set to 3 (Bad
BGP Identifier).
3.2. Connection Collision Detection
In case of collision detection, the BGP Identifiers of the peers
involved in the collision are compared and only the connection
initiated by the BGP speaker with the higher-valued BGP Identifier is
retained. Comparing BGP Identifiers is done by converting them to
host byte order and treating them as 16-octet unsigned integers.
3.3. Route Selection Decision
If a route is advertised by an IPv4 BGP speaker and an IPv6 BGP
speaker respectively, then the route advertised by the IPv6 BGP
speaker is selected; if a route is advertised by two IPv6 BGP
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speakers respectively, then their IPv6 BGP IDs are compared, and the
route advertised by the BGP speaker with the lower-valued BGP
Identifier is selected.
4. Security Considerations
TBD.
5. IANA Considerations
This document requests a new BGP Capability Code to be allocated by
IANA.
6. Normative References
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement
with BGP-4", RFC 5492, February 2009.
[RFC6286] Chen, E. and J. Yuan, "Autonomous-System-Wide Unique BGP
Identifier for BGP-4", RFC 6286, June 2011.
Authors' Addresses
Peng Fan
China Mobile
32 Xuanwumen West Street, Xicheng District
Beijing 100053
P.R. China
Email: fanpeng@chinamobile.com
Zhenqiang Li
China Mobile
32 Xuanwumen West Street, Xicheng District
Beijing 100053
P.R. China
Email: lizhenqiang@chinamobile.com
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