Information Technology Reference
In-Depth Information
Arrows indicate the directions in which prefixes are advertised. For clarity, arrows are
drawn only from the router that originates the prefix.
NOTE
Figure 8-2 shows the topology based on route reflection. In this topology, all core routers
(R1, R2, R4, and R5) are RRs, with access routers (R3, R6, and R7) as their respective
clients. Clients peer only with RRs in the same POP. All core routers are fully meshed.
Figure 8-2
RR-Based Topology
AS 200
R8
172.16.0.0/16
AS 100
RR
RR
Client
192.168.200.0/24
R1
R4
R6
192.168.201.0/24
192.168.202.0/24
R3
Client
R2
R5
R7
RR
RR
Client
Access routers here represent the ones that interconnect with customers or other networks.
Customer prefixes can be injected into BGP locally on access routers or exchanged via BGP
if customer routers are running BGP. To simplify the discussion, customer prefixes are
simulated in this chapter by injecting them statically on access routers.
NOTE
Figure 8-3 shows the confederation topology, in which each POP is a member AS in
confederation 100. A core router peers with other core routers with which it has direct
physical connections. Within each member AS, all BGP speakers are fully meshed.
