Users Guide

Example-Configuring IPv4 and IPv6 neighbors
The following example configurations show how to enable BGP and set up some peer under IPv4 and IPv6 address families.
To support your own IP addresses, interfaces, names, and so on, you can copy and paste from these examples to your CLI. Be
sure that you make the necessary changes.
Example-Configuring IPv4 and IPv6 neighbors
Example of enabling BGP and address family configuration in router (R1)
Following is an example to enable BGP and address family configuration for the neighbor R2 (20.20.20.2) in the router R1.
R1(conf)# router bgp 10
R1(conf-router_bgp)# neighbor 20.20.20.2 remote-as 200
R1(conf-router_bgp)# neighbor 20.20.20.2 no shutdown
R1(conf-router_bgp)# neighbor 2001::2 remote-as 200
R1(conf-router_bgp)# neighbor 2001::2 no shutdown
R1(conf-router_bgp)# neighbor 30.30.30.1 remote-as 20
R1(conf-router_bgp)# neighbor 30.30.30.1 no shutdown
R1(conf-router_bgp)# neighbor 3000::1 remote-as 300
R1(conf-router_bgp)# neighbor 3000::1 no shutdown
R1(conf-router_bgp)# no neighbor 3000::1 activate
R1(conf-router_bgp)# address-family ipv4 multicast
R1(conf-router_bgp_af)# neighbor 20.20.20.2 activate
R1(conf-router_bgp_af)# exit
R1(conf-router_bgp)# address-family ipv6 unicast
R1(conf-router_bgpv6_af)# neighbor 20.20.20.2 activate
R1(conf-router_bgpv6_af)# neighbor 2001::2 activate
R1(conf-router_bgpv6_af)#exit
The neighbors configured under CONFIGURATION-ROUTER-BGP mode and are defined using the neighbor remote-as
command exchange only IPv4 unicast address prefixes. If you want a neighbor to exchange other prefixes such as IPv4
multicast or IPv6 unicast, you have to explicitly activate the respective neighbor using neighbor activate command in the
respective IPv4 multicast or IPv6 unicast address family configuration. In the above example configuration, activating the
neighbor (20.20.20.2) under the IPv4 multicast address family enables the neighbor to exchange IPv4 muticast prefixes.
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
Border Gateway Protocol (BGP)
225