Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

Page: 49 / 742

Figure 7: Nontransit Service
IPv6 BGP Support
Most of the extensions and features available in BGP for IPv4 are also available for the
IPv6 address family, such as policy-based routing, redistributing routes to and from other
protocols, route aggregation, route flap dampening, and confederations. For a description
of IPv6, see
Configuring IPv6 in JunosE IP, IPv6, and IGP Configuration Guide .
Multiprotocol Extensions for BGP-4 (MP-BGP) allow the exchange of IPv6 routing
information over TCP IPv4 (Figure 8 on page 13) or TCP IPv6 transport (Figure 9 on
page 14).
Exchange of IPv6 Routing Information over TCP IPv4
Figure 8 on page 13 illustrates the exchange of IPv6 routing information over a TCP IPv4
connection.
Figure 8: IPv6 Routing over TCP IPv4
The E Series router’s MP-BGP implementation uses BGP update messages to announce
the feasible routes to an associated IPv6 BGP next hop and also to announce the
nonfeasible routes that need to be withdrawn from the peer. The E Series router
announces only IPv6 global addresses as the BGP next-hop address; it does not use the
optional link-local IPv6 address as the BGP next hop.
BGP determines the next-hop addresses to be announced by using the IPv4-compatible
IPv6 address. For example, the following table shows the translation of an IPv4 address.
IPv6 address IPv4 address
::10.1.1.1 10.1.1.1
When a BGP speaker receives a BGP update message carrying IPv6 feasible routes, the
speaker resolves the announced IPv6 BGP next hop by performing a route lookup to the
IPv6 address in the IPv6 route table.
13 Copyright © 2010, Juniper Networks, Inc.
Chapter 1: Configuring BGP Routing