3Com Switch 8800 Family Configuration Guide

378 CHAPTER 33: BGP CONFIGURATION
Configuring BGP Route
Reflector
To ensure the interconnection between IBGP peers, it is necessary to establish a
fully connected network. If there are many IBGP peers, large overhead is needed
to establish a fully connected network.
Route reflecting can solve the problem. Route reflector is the centralized point of
other routers, and other routers are called the clients. The client is the peer of the
route reflector and switching the routing information with it. The route reflector
will reflect the information in order among the clients.
Figure 90 The route reflector diagram
In Figure 90, Router C is a route reflector with two peer clients: Router A and
Router B. Router A sends to Router C the update packet from an external peer.
Router C sends the update packet to Router B. After using reflecting technology,
you do not need to establish a connection between Router A and Router B. You
only need to connect Router C to Router A and Router B respectively.
If a BGP router is not either a reflector or client, we call the BGP router non-client.
You still need connect non-clients to reflectors and non-clients.
You only need to configure route reflecting for the route reflector. When
configuring the route reflector, you must specify the routers to serve as clients.
Configuring an IBGP peer group as route reflector client
Perform the following configuration in BGP view.
This command works on IBGP peer groups only.
By default, all IBGP routes in an AS must be full-connected, and neighbors do not
advertise learned IBGP routes to one another.
Tabl e 382 Configure an IBGP peer group as route reflector client
Operation Command
Configure an IBGP peer group as route
reflector client
peer group-name reflect-client
Disable an IBGP peer group from being a
route reflector client
undo peer group-name reflect-client
Router
EBGP
EBGP
Route reflector
Route reflected
Route updated
Router A
Router B
Router C
Router
EBGP
EBGP
Route reflector
Route reflected
Route updated
Router A
Router B
Router C