CONFIGURE BGP PEER GROUP
BGP peer groups are used to simplify configuration and to improve performance. It can be used
when a router has a group of neighbors with the same update policies. The update is generated
once per group rather than for each neighbor.
To create and use a peer group follow next steps:
Type neighbor group-name peer-group to create a peer-group, where group-name is the name
that you give to the peer group.
next, enter neighbor ip-address peer-group group-name command, which will make a neighbor to
be part of peer group.
You can reset connections to member of a group by typing clear ip bgp peer-group group-name
command in exec mode.
Configure BGP peer group on BORDER router in AS 64520. Loopback ip addresses
are used as source of BGP packets. Let’s assume we have connection from
BORDER router to all devices in AS 64520. If not use BGP peer group,
configuration on BORDER router with the others will look like this:
router bgp 64520
neighbor 10.0.0.2 remote-as 64520
neighbor 10.0.0.2 update-source loopback 0
neighbor 10.0.0.2 next-hop-self
neighbor 10.0.0.3 remote-as 64520
neighbor 10.0.0.3 update-source loopback 0
neighbor 10.0.0.3 next-hop-self
neighbor 10.0.0.4 remote-as 64520
neighbor 10.0.0.4 update-source loopback 0
neighbor 10.0.0.4 next-hop-self
WITH THIS CONFIGURATION BGP UPDATES WILL BE GENERATED FOR EACH
NEIGHBOR, BUT IF USE PEER GROUP, UPDATES ARE GENERATED ONCE PER
PEER-GROUP. IF USE BGP PEER-GROUP, CONFIGURATION ON BORDER ROUTER
WILL LOOK LIKETHIS:
router bgp 64520
neighbor local peer-group
neighbor local remote-as 64520
neighbor local update-source loopback 0
neighbor local next-hop-self
neighbor 10.0.0.2 peer-group local
neighbor 10.0.0.3 peer-group local
neighbor 10.0.0.4 peer-group local
The name of BGP peer-group is local, this you can see from configuration above,
also we get a more robust configuration.