BGP peer group

We can minimize the neighbor command and memory process by using the peer group. With the help of peer group we can reduce the shortest path finding process also.

Now let have a iBGP peer between R1 - R2,  R1 - R3 and R2 - R3. Full mesh

R1(Config)#router bgp 100

R1(config-router)#neighbor iBGP_Peer peer-group

R1(config-router)#neighbor iBGP_Peer remote-as 100

R1(config-router)#neighbor iBGP_Peer update-source loopback 0

R1(config-router)#neighbor 150.2.2.2 peer-group iBGP_Peer

R1(config-router)#neighbor 150.3.3.3 peer-group iBGP_Peer

R2(Config)#router bgp 100

R2(config-router)#neighbor iBGP_Peer peer-group

R2(config-router)#neighbor iBGP_Peer remote-as 100

R2(config-router)#neighbor iBGP_Peer update-source loopback 0

R2(config-router)#neighbor 150.1.1.1 peer-group iBGP_Peer

R2(config-router)#neighbor 150.3.3.3 peer-group iBGP_Peer

R3(Config)#router bgp 100

R3(config-router)#neighbor iBGP_Peer peer-group

R3(config-router)#neighbor iBGP_Peer remote-as 100

R3(config-router)#neighbor iBGP_Peer update-source loopback 0

R3(config-router)#neighbor 150.2.2.2 peer-group iBGP_Peer

R3(config-router)#neighbor 150.1.1.1 peer-group iBGP_Peer

R1#sh bgp su

BGP router identifier 150.1.1.1, local AS number 100

BGP table version is 1, main routing table version 1

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

150.2.2.2       4   100       5       5        1    0    0 00:01:23        0

150.3.3.3       4   100       5       5        1    0    0 00:01:08        0

155.1.16.6      4   600      16      16        1    0    0 00:13:30        0

We formed iBGP neighborship :)