Exterior Border Gateway Protocol (EBGP) is a type of Border Gateway Protocol (BGP) used for routing between different autonomous systems. EBGP runs between BGP routers in separate autonomous systems, facilitating the exchange of routing information between these systems. It is implemented at the edge or border routers that interconnect different autonomous systems or organizations, including connections to the Internet.
Key differences between EBGP and Internal BGP (IBGP) include:
EBGP: Stands for External Border Gateway Protocol, runs between BGP routers in different autonomous systems, has a default Administrative Distance of 20, and allows routes received from an EBGP peer to be advertised to both EBGP and IBGP peers.
IBGP: Stands for Internal Border Gateway Protocol, runs between BGP routers within the same autonomous system, has a default Administrative Distance of 200, and restricts routes received from an IBGP peer from being advertised to another IBGP peer but can be advertised to an EBGP peer.