
Configuring BGP
BGP Overview
OmniSwitch AOS Release 7 Advanced Routing Configuration Guide
March 2011
page 3-9
Route Reflectors
Route reflectors are useful if the internal BGP mesh becomes very large. A route reflector is a concentra-
tion router for other BGP peers in the local network, acting as a focal point for internal BGP sessions.
Multiple client BGP routers peer with the central route server (the reflector). The router reflectors then
peer with each other. Although BGP rules state that routes learned via one IBGP speaker cannot be adver-
tised to another IBGP speaker, route reflection allows the router reflector servers to “reflect” routes,
thereby relaxing the IBGP standards.
Note.
This feature, which is used to minimize the number of IBGP sessions in an AS is not supported in
the IPv6 BGP environment.
The following illustration depicts two scenarios to demonstrate the benefit of using Route Reflectors:
In the diagram below, Clients 1, 2, and 3 peer with Reflector 1, and Clients 4, 5, and 6 peer with
Reflector2. Reflector 1 and 2 peer with each other. This allows each BGP speaker to maintain only one
BGP session, rather than a possible seven sessions, as in the diagram above.
AS 100 without Route Reflection