Configuring BGP
Configuring Advanced BGP Features
IPC-318
Cisco IOS IP Configuration Guide

Figure56 Simple BGP Model with a Route Reflector

The internal peers of the route reflector are divided into two groups: client peers and all the other routers in the autonomous system (nonclient peers). A route reflector reflects routes between these two groups. The route reflector and its client peers form a cluster. The nonclient peers must be fully meshed with each other, but the client peers need not be fully meshed. The clients in the cluster do not communicate with iBGP speakers outside their cluster.

Figure57 More Complex BGP Route Reflector Model

S4219
External
BGP
speaker
Partially meshed autonomous system
Route
reflector
Reflected
routes
Routes
Routes

Router A

Router B

Router A Router C

S4218
External
BGP
speaker
Routes
advertised
Route reflector
Cluster
Client Client Client
Nonclient
Nonclient
Nonclient
Partially meshed
autonomous system
Router A
Router B
Router G
Router F
Router E
Router C Router D
Router A