An engineer configures a route reflector cluster with two route reflectors in the same cluster ID. After convergence, some iBGP routes are missing on clients, and 'show ip bgp' shows the path with 'r' flag. What is the most likely explanation?
Route reflectors with the same cluster ID will reject routes from each other to prevent loops, leading to missing routes on clients.
Why this answer
When two route reflectors share the same cluster ID, they treat each other's updates as if from the same cluster. The route reflector loop prevention mechanism drops routes learned from another RR in the same cluster, causing route loss if the clients are not fully meshed.