Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 323)

Brocade Virtual ADX Switch and Router Guide 309
53-1003246-01
Chapter
9
Configuring BGP4+
The 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
The 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.
Address family configuration level
The implementation of BGP4+ includes a new configuration level: address family. For IPv6, Virtual
ADX currently supports the BGP4+ unicast address family configuration level only. The device
enters the BGP4+ unicast address family configuration level when you enter the following
command while at the global BGP configuration level:
Virtual ADX(config-bgp)# address-family ipv6 unicast
Virtual ADX(config-bgp-ipv6u)#
The (config-bgp-ipv6u)# prompt indicates that you are at the BGP4+ unicast address family
configuration level.
While at the BGP4+ unicast address family configuration level, you can access several commands
that allow you to configure BGP4+ unicast routes. The commands that you enter at this level apply
only to IPv6 unicast address family only. You can generate a configuration for BGP4+ unicast routes
that is separate and distinct from configurations for IPv4 unicast routes.
NOTE
The commands that you can access while at the IPv6 unicast address family configuration level are
also available at the IPv4 unicast configuration level. Where relevant, this section discusses and
provides IPv6-unicast-specific examples.
NOTE
Each address family configuration level allows you to access commands that apply to that particular
address family only. To enable a feature in a particular address family, you must specify any
associated commands for that feature in that particular address family. You cannot expect the
feature, which you may have configured in the BGP4 unicast address family, to work in the BGP4+
unicast address family unless it is explicitly configured in the BGP4+ unicast address family.