Figure 42: A Confederation of Subautonomous Systems
The following commands partially configure router Salem:
host1(config)#router bgp 64720
host1(config-router)#bgp confederation identifier 29
host1(config-router)#bgp confederation peers 64721 64722
host1(config-router)#neighbor 10.2.25.4 remote-as 64720
host1(config-router)#neighbor 10.2.25.8 remote-as 64721
host1(config-router)#neighbor 10.2.25.2 remote-as 325
The bgp confederation identifier command establishes router Salem as a member
of Confederation 29. The bgp confederation peers command specifies that sub-AS
64721 and sub-AS 64722 are members of the same confederation as the sub-AS that
includes router Salem. The neighbor remote-as commands specify the IBGP
connection with a neighbor in sub-AS 64720 and the EBGP connections with neighbors
in sub-AS 64721 and outside the confederation in AS 325.
Similarly, the following commands partially configure router Harvard:
host2(config)#router bgp 64721
host2(config-router)#bgp confederation identifier 29
host2(config-router)#bgp confederation peers 64720 64722
host2(config-router)#neighbor 10.2.25.7 remote-as 64720
From router Newport’s perspective, router Salem is simply a member of AS 29:
host3(config)#router bgp 325
146 â– Managing a Large-Scale AS
JUNOSe 11.1.x BGP and MPLS Configuration Guide