Border Gateway Protocol version 4 (BGP4) cannot support a multicast network topology that differs
from the network’s unicast topology. As a result, BGP4 was extended to include Multiprotocol BGP
(MBGP). MBGP allows you to support a multicast topology that is distinct from the network’s
unicast topology. For example, if you want to dedicate a link on your Internet router to multicast
traffic, you can use MBGP to handle the routes on that link.

A router with MBGP enabled learns MBGP routes from its neighbors in other autonomous systems
(ASs). An MBGP

Brocade’s implementation of IPv6 supports multi protocol BGP (MBGP) extensions, which allow
IPv6 BGP (known as BGP4+) to distribute routing information for protocols such as IPv4 BGP. The
supported protocols are identified by address families. The extensions allow a set of BGP4+ peers
to exchange routing information for multiple address families and sub-address families.

IPv6 MBGP functions similarly to IPv4 MBGP except for the following enhancements:

•

An IPv6 unicast address family and network layer reachability information (NLRI).

•

Next hop attributes that use IPv6 addresses.

NOTE

Brocade’s implementation of BGP4+ supports the advertising of routes among different address
families. However, it supports BGP4+ unicast routes only; it does not currently support BGP4+
multicast routes.

This chapter describes the following:

•

The address family configuration level for BGP4+.

•

How to configure BGP4+.

•

How to clear various BGP information, statistics, and counters.

•

How to display BGP4+ information and statistics.