Administrator Guide

Similarly, activating the neighbors (20.20.20.2 and 2001::2) under the IPv6 unicast address family enables the neighbor to
exchange IPv6 unicast prefixes. The neighbor (30.30.30.1) is activated by default for exchanging IPv4 unicast address prefixes,
but will not exchange IPv4 multicast and IPv6 unicast address prefixes since they are not activated under the respective
address family. If you want the neighbor (30.30.30.1) to exchange IPv4 multicast and/or IPv6 unicast prefixes, you have to
explicitly active the neighbor using neighbor activate command.
If you do not want a neighbor to exchange IPv4 unicast prefixes, you have to manually deactivate the peer with the no
neighbor activate command under the CONFIGURATION-ROUTER-BGP mode. If any neighbor is already activated to
exchange IPv4 multicast or IPv6 unicast prefixes, exchanging of prefixes can be deactivated using no neighbor activate
command under the IPv4 multicast or IPv6 unicast address family. In the above example configuration, the peer (3000::1) is
deactivated from exchanging IPv4 unicast prefixes.
The show ip bgp summary or show ip bgp ipv4 unicast summary displays IPv4 unicast address family
configuration. In a dual stack scenario, to view the specific IPv4 multicast or IPv6 unicast address family configuration, use
show ip bgp ipv4 multicast summary or show ip bgp ipv6 unicast summary commands.
Following is the sample output for show ip bgp summary command.
R1#show ip bgp summary
BGP router identifier 1.1.1.1, local 10
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
3 neighbor(s) using 40960 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.2 200 10 20 0 0 0 00:06:11 0
30.30.30.1 20 0 0 0 0 0 00:00:00 0
2001::2 200 40 45 0 0 0 00:03:14 0
The same output will be displayed when using show ip bgp ipv4 unicast summary command.
Following is the sample output of show ip bgp ipv4 multicast summary command.
R1# show ip bgp ipv4 multicast summary
BGP router identifier 1.1.1.1, local AS number 10
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
1 neighbor(s) using 24576 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.2 200 10 20 0 0 0 00:06:11 0
R1#
Following is the output of show ip bgp ipv6 unicast summary command for the above configuration example.
R1#show ip bgp ipv6 unicast summary
BGP router identifier 1.1.1.1, local AS number 10
BGP local RIB : Routes to be Added 0, Replaced 0, Withdrawn 0
2 neighbor(s) using 24576 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
20.20.20.2 200 10 20 0 0 0 00:06:11 0
2001::2 200 40 45 0 0 0 00:03:14 0
R1#
Example of enabling BGP and address family configuration in router (R2)
Following is an example to enable BGP and address family configuration for the neighbor R1 (20.20.20.1) in the router R2.
R2(conf)# router bgp 200
R2(conf-router_bgp)# neighbor 20.20.20.1 remote-as 10
R2(conf-router_bgp)# neighbor 20.20.20.1 no shutdown
R2(conf-router_bgp)# neighbor 2001::1 remote-as 10
R2(conf-router_bgp)# neighbor 2001::1 no shutdown
R2(conf-router_bgp)# address-family ipv4 multicast
R2(conf-router_bgp_af)# neighbor 20.20.20.1 activate
R2(conf-router_bgp_af)# exit
R2(conf-router_bgp)# address-family ipv6 unicast
R2(conf-router_bgpv6_af)# neighbor 20.20.20.1 activate
R2(conf-router_bgpv6_af)# neighbor 2001::1 activate
R2(conf-router_bgpv6_af)#exit
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Border Gateway Protocol (BGP)