Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing (RFC2545)
Original Publication Date: 1999-Mar-01
Included in the Prior Art Database: 2000-Sep-13
Internet Society Requests For Comment (RFCs)
P. Marques: AUTHOR [+2]
BGP-4 Multiprotocol Extensions [BGP-MP] defines the format of two BGP attributes (MP_REACH_NLRI and MP_UNREACH_NLRI) that can be used to announce and withdraw the announcement of reachability information. This document defines how compliant systems should make use of those attributes for the purpose of conveying IPv6 routing information.
Network Working Group P. Marques
Request for Comments: 2545 cisco Systems, Inc.
Category: Standards Track F. Dupont
Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing
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 (C) The Internet Society (1999). All Rights Reserved.
BGP-4 Multiprotocol Extensions [BGP-MP] defines the format of two BGP
attributes (MP_REACH_NLRI and MP_UNREACH_NLRI) that can be used to
announce and withdraw the announcement of reachability information.
This document defines how compliant systems should make use of those
attributes for the purpose of conveying IPv6 routing information.
The BGP-4 protocol [BGP-4] in particular, and path vector routing
protocols in general, are mostly independent of the particular
Address Family for which the protocol is being used.
IPv6 falls under the generic category of protocols for which BGP-4 is
suitable and, unless stated otherwise in this document, the BGP-4
procedures to apply when using BGP-4 to carry IPv6 reachability
information are those defined in [BGP-4] and in subsequent documents
that extend or update the BGP-4 specification.
In terms of routing information, the most significant difference
between IPv6 and IPv4 (for which BGP was originally designed) is the
fact that IPv6 introduces scoped unicast addresses and defines
particular situations when a particular address scope must be used.
This document concerns itself essentially with the necessary rules to
accommodate IPv6 address scope requirements.
2. IPv6 Address Scopes
IPv6 defines 3 unicast address scopes [ADDR-ARCH]: global, site-local
and link-local. Site-local addresses are non-link-local address which
are valid within the scope of a "site" and cannot be exported beyond
it. As this document makes no assumption on the characteristics of a
particular routing realm where BGP-4 is used, it makes no distinction
between global and site-local addresses and refers to both as
"global" or "non-link-local". Network administrators must however
respect address scope restrictions and should be aware that the
concepts of a BGP-4 routing domain and "site" are orthogonal notions
and that they may or may not coincide in a given situation.
Companion IPv6 specifications further define that only link-local
address can be used when generating ICMP Redirect Messages [ND] a...