RFC 1397 (rfc1397) - Page 2 of 2
Default Route Advertisement In BGP2 and BGP3 Version of The Border Gateway Protocol
Alternative Format: Original Text Document
RFC 1397 Default Routes in Old BGPs January 1993
gateway that can be used as a default next hop to destinations that
are not listed in the BGP peer's routing table. The value of the
ORIGIN attribute should be 2 (INCOMPLETE). The AS_PATH attribute
should be constructed according to the same rules that apply to a
conventional network advertisement.
If multiple default routes are advertised by a BGP speaker, the
INTER-AS-METRIC path attribute can be included in the corresponding
UPDATE messages to express preference levels for entry points to the
same AS.
The UNREACHABLE path attribute is used to indicate that a previously
advertised default route has become unreachable.
UPDATE messages containing the default route advertisements should be
handled according to the rules that apply to all other UPDATE
messages. If multiple default route are acquired by a BGP speaker, a
route is selected according to the local policies adopted by this BGP
speaker.
References
[1] Lougheed, K., and Y. Rekhter, "A Border Gateway Protocol (BGP)",
RFC 1163, cisco Systems, T.J. Watson Research Center, IBM Corp.,
June 1990.
[2] Lougheed, K., and Y. Rekhter, "A Border Gateway Protocol 3 (BGP-
3)", RFC 1267, cisco Systems, T.J. Watson Research Center, IBM
Corp., October 1991.
[3] Rekhter, Y., and T. Li, "A Border Gateway Protocol 4 (BGP-4)",
Work in Progress, T.J. Watson Research Center, IBM Corp., cisco
Systems, December 1992.
Security Considerations
Security issues are not discussed in this memo.
Author's Address
Dimitry Haskin
Bolt, Beranek & Newman
150 Cambridge Park Drive
Cambridge, MA 02140
Phone: 617-873-8609
Email:
Haskin