BGP Identifier

BGP Identifier
The BGP Identifier field is 4 bytes long and contains the BGP identifier of the
sending BGP speaker. The
BGP identifier
is similar to the router ID (RID) for OSPF. It identifies
the particular BGP speaker. Like the OSPF RID, the BGP identifier will be the highest loopback
IP address on the router. If a loopback doesn’t exist on the router, it will be the highest IP
address configured for any interface on the router. The BGP identifier is set during the startup
process of BGP. In other words, once the BGP identifier is set, it will not change unless you
restart the BGP process. It is a good idea when using BGP to configure a loopback interface to
set the BGP identifier.