The characteristics of BGP follow:
- BGP is an exterior gateway protocol (EGP) used in routing in the Internet. It is an interdomain routing protocol.
- BGP is a path vector routing protocol suited for strategic routing policies.
- BGP uses TCP Port 179 to establish connections with neighbors.
- BGPv4 implements CIDR.
- eBGP is for external neighbors. It's used between separate autonomous systems.
- iBGP is for internal neighbors. It's used within an AS.
- BGP uses several attributes in the routing-decision algorithm.
- BGP uses confederations and route reflectors to reduce BGP peering overhead.
- The MED (metric) attribute is used between autonomous systems to influence inbound traffic.
- Weight is used to influence the path of outbound traffic from a single router, configured locally.