User guide

13-4 E
XTREME
W
ARE
S
OFTWARE
U
SER
G
UIDE
E
XTERIOR
G
ATEWAY
R
OUTING
P
ROTOCOLS
Figure 13-1: Route reflectors
R
OUTE
C
ONFEDERATIONS
BGP requires networks to use a fully-meshed router configuration. This requirement
does not scale well, especially when BGP is used as an interior gateway protocol. One
way to reduce the size of a fully-meshed AS is to divide the AS into multiple
sub-autonomous systems and group them into a routing confederation. Within the
confederation, each sub-AS must be fully-meshed. The confederation is advertised to
other networks as a single AS.
R
OUTE CONFEDERATION EXAMPLE
Figure 13-2 shows an example of a confederation.
EW_042
Client
Client
Route Reflector
Non-client
Cluster