Border Gateway Protocol is a kind of exterior gateway protocol mainly designed to exchange the information related to routing and the reachability in the internet.

The neighbours in the BGP are called the peers that are linked by the manual configuration to create the sessions on the port.

This protocol is considered is called the vector protocol for path but it is also called as distance-vector routing protocol.

The Border Gateway Protocol performs the routing decisions which are based on the paths, network policies done by the network administrator .

BGP may be used for routing within an autonomous system. In this application it is referred to as Interior Border Gateway Protocol, Internal BGP, or iBGP.

In order to make decisions in its operations with peers, a BGP peer uses a simple finite state machine (FSM) that consists of six states: Idle; Connect; Active; OpenSent; OpenConfirm; and Established.

Most Internet service providers must use BGP to establish routing between one another.