A.8.b) Configuration sample
- Notice that you need to add static routes between the links so load-sharing can be done through the loopback interface.
We need to add an additional hop for the Ebgp session; this is because the Ebgp session is established to the loopback interface of your neighbor who is one step below the physicals interfaces.
For that we will need to specify the “ebgp-multihop 2” instruction.
The number of hops is 2 here, but can be more. It is not important if the number is higher than the minimum requirement, however the contrary will fail the session.
router bgp 1000
neighbor 188.8.131.52 remote-as 400
neighbor 184.108.40.206 description 3xSTM4-ISP-C
neighbor 220.127.116.11 ebgp-multihop 2
neighbor 18.104.22.168 update-source Loopback0
neighbor 22.214.171.124 version 4
neighbor 126.96.36.199 activate
neighbor 188.8.131.52 send-community both
neighbor 184.108.40.206 route-map AS-400-INCOMING in
neighbor 220.127.116.11 route-map AS-400-OUTGOING out
ip route 18.104.22.168 255.255.255.255 POS1/1/2 22.214.171.124 name Loopback-Peer-AS400
ip route 126.96.36.199 255.255.255.255 POS1/1/1 188.8.131.52 name Loopback-Peer-AS400
ip route 184.108.40.206 255.255.255.255 POS1/1/3 220.127.116.11 name Loopback-Peer-AS400
route-map AS-400-INCOMING permit 10
match as-path 1
set local preference 90
route-map AS-400-OUTGOING permit 20
match as-path 2
set community 400:70
ip as-path access-list 1 permit ^400_
ip as-path access-list 2 permit ^$