Cisco NCS 5500 Series Configuration Manual page 31

Implementing BGP
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation identifier 5
Specifies a BGP confederation identifier.
Step 4 bgp confederation peers as-number
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1091
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1092
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1093
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1094
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1095
RP/0/RP0/CPU0:router(config-bgp)# bgp confederation peers 1096
Specifies that the BGP autonomous systems belong to a specified BGP confederation identifier. You can associate
multiple AS numbers to the same confederation identifier, as shown in the example.
Step 5
commit
BGP Confederation: Example
The following is a sample configuration that shows several peers in a confederation. The confederation consists
of three internal autonomous systems with autonomous system numbers 6001, 6002, and 6003. To the BGP
speakers outside the confederation, the confederation looks like a normal autonomous system with autonomous
system number 666 (specified using the bgp confederation identifier command).
In a BGP speaker in autonomous system 6001, the bgp confederation peers command marks the peers from
autonomous systems 6002 and 6003 as special eBGP peers. Hence, peers 171.16 .232.55 and 171.16 .232.56
get the local preference, next hop, and MED unmodified in the updates. The router at 171 .19 .69.1 is a normal
eBGP speaker, and the updates received by it from this peer are just like a normal eBGP update from a peer
in autonomous system 666.
router bgp 6001
bgp confederation identifier 666
bgp confederation peers
address-family ipv4 unicast
address-family ipv4 unicast
address-family ipv4 unicast
6002
6003
exit
neighbor 171.16.232.55
remote-as 6002
exit
neighbor 171.16.232.56
remote-as 6003
exit
neighbor 171.19.69.1
remote-as 777
BGP Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.2.x
BGP Routing Domain Confederation
21