Border Gateway Protocol - CCIE Routing and Switching Exam Certification Guide - page 448

inbound soft-reconfiguration is enabled. Each neighbor is assigned to the peer group with the
neighbor ip-address peer-group group-name command.
Example 9-14 Example of Peer Group Configuration
router bgp 65500
no synchronization
neighbor globalnet peer-group
neighbor globalnet remote-as 65500
neighbor globalnet update-source Loopback0
neighbor globalnet next-hop-self
neighbor globalnet version 4
neighbor globalnet soft-reconfiguration inbound
neighbor 1.25.1.160 peer-group globalnet
neighbor 1.25.1.161 peer-group globalnet
neighbor 1.25.1.164 peer-group globalnet
neighbor 1.25.1.165 peer-group globalnet
neighbor 1.25.1.166 peer-group globalnet
neighbor 1.25.1.167 peer-group globalnet
neighbor 1.25.1.168 peer-group globalnet
neighbor 1.25.1.169 peer-group globalnet
neighbor 1.25.1.170 peer-group globalnet
neighbor 1.25.1.171 peer-group globalnet
neighbor 1.25.1.172 peer-group globalnet
neighbor 1.25.1.173 peer-group globalnet
neighbor 1.25.1.174 peer-group globalnet
Route Reflectors
Network administrators can use route reflectors to reduce the number of required mesh links
between iBGP peers. Some routers are selected to become the route reflectors to serve several
other routers that act as clients. Route reflectors allow a router to advertise or reflect routes to
clients. The route reflector and its clients form a cluster. All client routers in the cluster peer
with the route reflectors within the cluster. The route reflectors also peer with all other route
reflectors in the internetwork. A cluster can have more than one route reflector.
In Figure 9-9, without route reflectors, all iBGP routers are configured in an iBGP mesh,
as required by the protocol. When Routers A and G become route reflectors, they peer with
Routers C and D. Router B becomes a route reflector for Routers E and F. Router A, B, and
G peer among each other.