3-17. bgp router-id ip-address

Syntax Description:

  • ip-address— IP address to use for the BGP router ID.

Purpose: To explicitly set the BGP router ID. BGP normally uses the highest IP address assigned to an interface as the router ID. If loopback interfaces are used, the BGP router ID is the highest address assigned to a loopback interface, regardless of the IP addresses assigned to any physical interface.

Cisco IOS Software Release: 10.0

Configuration Example: BGP Router IDs

The scenario in Figure 3-12 is used to demonstrate the three possibilities for determining a BGP router ID. Initially, configure Router B without using loopback interfaces.

Figure 3-12. Scenario Used to Demonstrate BGP Router IDs
Router A
router bgp 1
 neighbor 10.1.1.2 remote-as ...

Get Cisco® BGP-4 Command and Configuration Handbook (CCIE Professional Development) now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial