9.2 BGP router

First of all you must configure BGP router with router bgp command. To configure BGP router, you need AS number. AS number is an identification of autonomous system. BGP protocol uses the AS number for detecting whether the BGP connection is internal one or external one.

AS number is a digit between 1 and 65535. The use of AS numbers is described in RFC1930. AS numbers 64512 through 65535 are defined as private AS numbers. Private AS numbers must not to be advertised in the global Internet.

Command: router bgp as-number {}

Enable a BGP protocol process with the specified as-number. After this statement you can input any BGP Commands. You can not create different BGP process under different as-number without specifying multiple-instance (see section 9.12.1 Multiple instance).

Command: no router bgp as-number {}

Destroy a BGP protocol process with the specified as-number.

BGP Command: bgp router-id router-id {}

This command specifies the router-ID. If bgpd connects to zebra it gets interface and address information. In that case default router ID value is selected as the largest IP Address of the interfaces. When router zebra is not enabled bgpd can't get interface information so router-id is set to 0.0.0.0. So please set router-id by hand.