BGP Next-Hop Processing

BGP Next-Hop Processing:

  • For eBGP peers: Change next hop address on advertised routes.
  • For iBGP peers: Do not change next hop address on advertised routes.

This can result in BGP routes being advertised where the next hop is unreachable so the neighbor does not populate the routing table with routes from BGP.  It is resolved by using “next-hop-self” command on the router advertising the external BGP routes to the iBGP neighbor:

router bgp 5500
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 5500
neighbor 1.1.1.1 update-source Loopback4
 neighbor 1.1.1.1 next-hop-self

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.