9.1 Route Reflectors
9.1.3 Internal peers with route reflectors
If you designate one of the routers in AS 100 as a route reflector (see the figure), it will act as a concentration point, or route reflector server, for other routers, which act as route reflector clients. The clients peer with the route reflector and exchange routing information with it. In turn, the route reflector will pass on, or reflect, the information to the clients.

In the figure, RTA receives an update from an external peer and passes it on to RTB, which is configured as a route reflector server with two clients, RTA and RTC. RTB will reflect the update from client RTA to client RTC.