3.7.b Implement and troubleshoot IBGP and EBGP

3.7.b [i] EBGP, IBGP

r3 and r4 are peering using loopback interfaces, update source, and ebgp multihop because they are  in different as’s… although the loopback is on that same router it is considered another hop and the default ttl has to be increased… no surprise there…

R3#sh run | b router bgp
router bgp 123
bgp log-neighbor-changes
neighbor my-as peer-group
neighbor my-as remote-as 123
neighbor my-as update-source Loopback1
neighbor 1.1.1.1 peer-group my-as
neighbor 1.1.1.1 password cisco
neighbor 2.2.2.2 peer-group my-as
neighbor 4.4.4.4 remote-as 45
 neighbor 4.4.4.4 ebgp-multihop 2
 neighbor 4.4.4.4 update-source Loopback1

R4#sh run | b router bgp
router bgp 45
bgp log-neighbor-changes
neighbor 3.3.3.3 remote-as 123
 neighbor 3.3.3.3 ebgp-multihop 2
 neighbor 3.3.3.3 update-source Loopback1

the tcp brief output shows which side intitiated the connection because the destination port is 179… r3’s tcp port to 4.4.4.4 is random…

tcpinitiate