3Com 10014299 manual By default, an aggregate is disabled, Aggregate address mask, As-set

460 CHAPTER 30: CONFIGURING BGP

Add a piece of routing aggregate	aggregate address mask	[ as-set ] [
information to the BGP routing table	detail-suppressed ] [
	suppress-policy policy-name		] [
	origin-policy policy-name]		[
	attribute-policy policy-name]
Delete a piece of routing aggregate	undo aggregate address	mask
information to the BGP routing table

By default, an aggregate is disabled.

Configure BGP Route To guarantee the connectivity between the IBGP peers, an all-closed network Reflector should exist between IBGP peers. In some networks, the internal BGP network can

become very large (with more than one hundred sessions in each router), resulting in huge overhead. The route reflector designates a central router as the core of the internal sessions. Multiple BGP routers can become peers with this central router, and then multiple route reflectors can be peers with each other.

Since the route reflector is the center of other routers, other routers are called client routers from the viewpoint of the reflector. The client routers are peers of the route reflector and exchange routing information. The route reflector forwards (reflects) information among the client routers in turn.

As shown in the following diagram, Router A receives an update from an external peer and transfers it to Router B. Router B is a route reflector, which has two clients: Router A and Router C.

Router B can reflect the routing update from client Router A to client Router C. In this instance, the session between Router A and Router C is unnecessary because the route reflector forwards the BGP information to Router C.

Figure 152 Schematic diagram of route reflector

Route Reflector Router B

Reflected router

Update route

EBGP Router A Router C EBGP

The route reflector divides the IBGP peers into two types: client and non-client. Using the peer reflect-client command, you can configure the internal neighbors that can communicate with the route reflector. The neighbors are called the client group members of the route reflector, and other neighbors that are not configured as the non-clients are the non-client group members of the route reflector.