Route reflector

The route reflector (RR) offers an alternative to the logical full-mesh requirement of internal border gateway protocol (iBGP). A RR acts as a focal point for iBGP sessions. The purpose of the RR is concentration. Multiple BGP routers can peer with a central point, the RR - acting as a route reflector server - rather than peer with every other router in a full mesh. All the other iBGP routers become route reflector clients.

This approach, similar to OSPF's DR/BDR feature, provides large networks with added iBGP scalability. A network requiring more than 100 statements just to define the remote-as of each peer quickly becomes a headache to administer. The RR can offer a viable solution for the larger networks administered by ISPs.

Rules

RR servers propagate routes inside the AS based on the following rules:
* If a route is received from nonclient peer, reflect to clients only.
* If a route is received from a client peer, reflect to all nonclient peers and also to client peers, except the originator of the route.
* If a route is received from an EBGP peer, reflect to all client and nonclient peers.