RFC 1773 (rfc1773) - Page 2 of 9
Experience with the BGP-4 protocol
Alternative Format: Original Text Document
RFC 1773 Experience with the BGP-4 Protocol March 1995
Documentation
BGP is an inter-autonomous system routing protocol designed for
TCP/IP internets. Version 1 of the BGP protocol was published in RFC
1105. Since then BGP Versions 2, 3, and 4 have been developed.
Version 2 was documented in RFC 1163. Version 3 is documented in RFC
1267. The changes between versions 1, 2 and 3 are explained in
Appendix 2 of [2]. All of the functionality that was present in the
previous versions is present in version 4.
BGP version 2 removed from the protocol the concept of "up", "down",
and "horizontal" relations between autonomous systems that were
present in version 1. BGP version 2 introduced the concept of path
attributes. In addition, BGP version 2 clarified parts of the
protocol that were "under-specified".
BGP version 3 lifted some of the restrictions on the use of the
NEXT_HOP path attribute, and added the BGP Identifier field to the
BGP OPEN message. It also clarifies the procedure for distributing
BGP routes between the BGP speakers within an autonomous system.
BGP version 4 redefines the (previously class-based) network layer
reachability portion of the updates to specify prefixes of arbitrary
length in order to represent multiple classful networks in a single
entry as discussed in [5]. BGP version 4 has also modified the AS-
PATH attribute so that sets of autonomous systems, as well as
individual ASs may be described. In addition, BGP version for has
redescribed the INTER-AS METRIC attribute as the MULTI-EXIT
DISCRIMINATOR and added new LOCAL-PREFERENCE and AGGREGATOR
attributes.
Possible applications of BGP in the Internet are documented in [3].
The BGP protocol was developed by the IDR Working Group of the
Internet Engineering Task Force. This Working Group has a mailing
list, , where discussions of protocol features and
operation are held. The IDR Working Group meets regularly during the
quarterly Internet Engineering Task Force conferences. Reports of
these meetings are published in the IETF's Proceedings.
MIB
A BGP-4 Management Information Base has been published [4]. The MIB
was written by Steve Willis (Wellfleet), John Burruss (Wellfleet),
and John Chu (IBM).
Apart from a few system variables, the BGP MIB is broken into two
tables: the BGP Peer Table and the BGP Received Path Attribute Table.
Traina