question about filtering routes to an IBGP neighbor

[west33637]

hello all. can I filter routes going to an IBGP peer? For example, I have 2 IBGP peers and one of the peers is configured as such.

ip prefix-list filter seq 5 permit 0.0.0.0/0
ip prefix-list filter seq 10 permit 10.0.0.0/8 le 32
ip prefix-list filter seq 15 permit 15.0.0.0/16 le 32
!
router bgp 63313
no synchronization
bgp log-neighbor-changes
neighbor 10.10.10.10 remote-as 63313
neighbor 10.10.10.10 prefix-list filter out

can this be done? Is there any reason why I cant do this? just to provide further info, the ibgp peer (10.10.10.10) is the AS boundary router.

Thanks

[Peter Paluch · Accepted solution]

Hello,

Technically, there are absolutely no problems with filtering outgoing routes to an iBGP peer. It is perfectly allowed. Of course, the net result of this filtering and its positive or negative impact depends on what do you want to achieve with the route filtering, and whether the iBGP neighbor has other choices to reach the networks that have been filtered out.

Best regards,

Peter