RFC 2858 (rfc2858) - Page 1 of 11
Multiprotocol Extensions for BGP-4
Alternative Format: Original Text Document
Network Working Group T. Bates
Request for Comments: 2858 Y. Rekhter
Obsoletes: 2283 Cisco Systems
Category: Standards Track R. Chandra
Redback Networks Inc
D. Katz
Juniper Networks
June 2000
Multiprotocol Extensions for BGP-4
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
Currently BGP-4 [BGP-4] is capable of carrying routing information
only for IPv4 [IPv4]. This document defines extensions to BGP-4 to
enable it to carry routing information for multiple Network Layer
protocols (e.g., IPv6, IPX, etc...). The extensions are backward
compatible - a router that supports the extensions can interoperate
with a router that doesn't support the extensions.
This document obsoletes RFC 2283.
1. Overview
The only three pieces of information carried by BGP-4 that are IPv4
specific are (a) the NEXT_HOP attribute (expressed as an IPv4
address), (b) AGGREGATOR (contains an IPv4 address), and (c) NLRI
(expressed as IPv4 address prefixes). This document assumes that any
BGP speaker (including the one that supports multiprotocol
capabilities defined in this document) has to have an IPv4 address
(which will be used, among other things, in the AGGREGATOR
attribute). Therefore, to enable BGP-4 to support routing for
multiple Network Layer protocols the only two things that have to be
added to BGP-4 are (a) the ability to associate a particular Network
Layer protocol with the next hop information, and (b) the ability to
Bates, et al. Standards Track