IBGP Load Balancing with BGP Additional Paths

In the previous lab exercise, you implemented IBGP load balancing across prefixes received by two WAN edge routers. The load balancing worked because you did not use BGP route reflectors in your autonomous system. Like any other BGP router, BGP route reflectors send their best routes to their clients; in your network, the IBGP clients of the BGP route reflector receive a single path to the external prefix.

You can use the BGP Additional Paths functionality to make the BGP route reflector send more than one best path to its clients, resulting in IBGP load balancing on BGP route reflector clients. You’ll practice that in this lab exercise.