As Confederations - Cisco Nexus 3000 Series Configuration Manual

Information About Advanced BGP
S e n d d o c u m e n t c o m m e n t s t o n e x u s 3 k - d o c f e e d b a c k @ c i s c o . c o m
Figure 6-1
AS20
Z
iBGP networks are fully meshed. Each iBGP peer has a direct connection to all other iBGP peers to
prevent network loops.
You should configure a separate interior gateway protocol in the iBGP network.
Note
This section includes the following topics:
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AS Confederations

A fully meshed iBGP network becomes complex as the number of iBGP peers grows. You can reduce
the iBGP mesh by dividing the autonomous system into multiple subautonomous systems and grouping
them into a single confederation. A confederation is a group of iBGP peers that use the same autonomous
system number to communicate to external networks. Each subautonomous system is fully meshed
within itself and has a few connections to other subautonomous systems in the same confederation.
Figure 6-2
confederation.
Figure 6-2
AS20
Z
Cisco Nexus 3000 Series NX-OS Unicast Routing Configuration Guide, NX-OS Release 5.0(3)U1(1)
6-4
iBGP Network
AS10
A
eBGP
iBGP
B
AS Confederations, page 6-4
Route Reflector, page 6-5
shows the BGP network from
AS Confederation
AS10
AS1
eBGP
iBGP
C
iBGP
iBGP
iBGP
D
Figure 6-1, split into two subautonomous systems and one
A
AS2
Confederation
peers
B
Chapter 6 Configuring Advanced BGP
iBGP
C
iBGP
D