To specify a BGP confederation identifier, use the bgp confederation identifier router configuration command. To remove the confederation identifier, use the no form of this command.
bgp confederation identifier autonomous-system
no bgp confederation identifier autonomous-system
autonomous-system Autonomous system number that internally includes multiple autonomous systems.
No confederation identifier is configured.
Router configuration
| Release | Modification | 10.3 | This command was introduced. |
|---|
Another way to reduce the IBGP mesh is to divide an autonomous system into multiple autonomous systems and group them into a single confederation. Each autonomous system is fully meshed within itself, and has a few connections to another autonomous system in the same confederation. Even though the peers in different autonomous systems have EBGP sessions, they exchange routing information as if they are IBGP peers. Specifically, the next-hop and local preference information is preserved. This enables to you to retain a single Interior Gateway Protocol (IGP) for all the autonomous systems. To the outside world, the confederation looks like a single autonomous system.
In the following example, the autonomous system is divided into autonomous systems 4001, 4002, 4003, 4004, 4005, 4006, and 4007 and identified by the confederation identifier 5. Neighbor 1.2.3.4 is someone inside your routing domain confederation. Neighbor 3.4.5.6 is someone outside your routing domain confederation. To the outside world, there appears to be a single autonomous system with the number 5.
router bgp 4001 bgp confederation identifier 5 bgp confederation peers 4002 4003 4004 4005 4006 4007 neighbor 1.2.3.4 remote-as 4002 neighbor 3.4.5.6 remote-as 510
| Command | Description |
|---|---|
| bgp confederation peers | Configures the autonomous systems that belong to the confederation. |
Printed for apswan@ctr.ap.nic.in on Wed Mar 5 22:32:57 PST 2003
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