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 18.104.22.168 remote-as 400
neighbor 22.214.171.124 description 3xSTM4-ISP-C
neighbor 126.96.36.199 ebgp-multihop 2
neighbor 188.8.131.52 update-source Loopback0
neighbor 184.108.40.206 version 4
neighbor 220.127.116.11 activate
neighbor 18.104.22.168 send-community both
neighbor 22.214.171.124 route-map AS-400-INCOMING in
neighbor 126.96.36.199 route-map AS-400-OUTGOING out
ip route 188.8.131.52 255.255.255.255 POS1/1/2 184.108.40.206 name Loopback-Peer-AS400
ip route 220.127.116.11 255.255.255.255 POS1/1/1 18.104.22.168 name Loopback-Peer-AS400
ip route 22.214.171.124 255.255.255.255 POS1/1/3 126.96.36.199 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 ^$