Concept Guide

!
interface TengigabitEthernet 3/21
ip address 10.0.2.3/24
no shutdown
R3(conf-if-te-3/21)#
R3(conf-if-te-3/21)#router bgp 100
R3(conf-router_bgp)#show config
!
router bgp 100
R3(conf-router_bgp)#neighbor 10.0.3.31 remote 99
R3(conf-router_bgp)#neighbor 10.0.3.31 no shut
R3(conf-router_bgp)#neighbor 10.0.2.2 remote 99
R3(conf-router_bgp)#neighbor 10.0.2.2 no shut
R3(conf-router_bgp)#show config
!
router bgp 100
neighbor 10.0.3.31 remote 99
neighbor 10.0.3.31 no shut
neighbor 10.0.2.2 remote 99
neighbor 10.0.2.2 no shut
Example of Enabling Peer Groups (Router 1)
conf
R1(conf)#router bgp 99
R1(conf-router_bgp)# network 192.168.128.0/24
R1(conf-router_bgp)# neighbor AAA peer-group
R1(conf-router_bgp)# neighbor AAA no shutdown
R1(conf-router_bgp)# neighbor BBB peer-group
R1(conf-router_bgp)# neighbor BBB no shutdown
R1(conf-router_bgp)# neighbor 192.168.128.2 peer-group AAA
R1(conf-router_bgp)# neighbor 192.168.128.3 peer-group BBB
R1(conf-router_bgp)#
R1(conf-router_bgp)#show config
!
router bgp 99
network 192.168.128.0/24
neighbor AAA peer-group
neighbor AAA no shutdown
neighbor BBB peer-group
neighbor BBB no shutdown
neighbor 192.168.128.2 remote-as 99
neighbor 192.168.128.2 peer-group AAA
neighbor 192.168.128.2 update-source Loopback 0
neighbor 192.168.128.2 no shutdown
neighbor 192.168.128.3 remote-as 100
neighbor 192.168.128.3 peer-group BBB
neighbor 192.168.128.3 update-source Loopback 0
neighbor 192.168.128.3 no shutdown
R1#
R1#show ip bgp summary
BGP router identifier 192.168.128.1, local AS number 99
BGP table version is 1, main routing table version 1
1 network entrie(s) using 132 bytes of memory
3 paths using 204 bytes of memory
BGP-RIB over all using 207 bytes of memory
2 BGP path attribute entrie(s) using 96 bytes of memory
2 BGP AS-PATH entrie(s) using 74 bytes of memory
2 neighbor(s) using 8672 bytes of memory
Neighbor AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/Pfx
192.168.128.2 99 23 24 0 0 0 00:06:11 0
Example of Enabling Peer Groups (Router 2)
R2#conf
R2(conf)#router bgp 99
R2(conf-router_bgp)# neighbor CCC peer-group
R2(conf-router_bgp)# neighbor CC no shutdown
R2(conf-router_bgp)# neighbor BBB peer-group
R2(conf-router_bgp)# neighbor BBB no shutdown
R2(conf-router_bgp)# neighbor 192.168.128.1 peer AAA
212
Border Gateway Protocol (BGP)