BGP

BGP stands for Border Gateway Protocol which is a dynamic routing path vector protocol. Border Gateway Protocol (BGP) is described by RFC 1267, 1268, 1497, 1771 (version 4). Border Gateway Protocol controls routing based on network rules or policies and uses TCP as a transport protocol. When two systems are using BGP, they establish a TCP connection, then send each other their BGP routing tables. BGP uses route aggregation to keep the size of routing tables smaller. BGP supports classless interdomain routing and uses distance vectoring.

Border Gateway protocol detects failures by sending periodic keep alive messages to its neighbors every 30 seconds. BGP exchanges information about reachable networks with other BGP systems including the full path of systems that are between them.