Border Gateway Protocol

The Border Gateway Protocol (usually known by its acronym BGP) is a routing protocol in the TCP/IP protocol suite; specifically, it is an EGP, used for providing the information needed for doing path selection across a connected group of Autonomous Systems.

It is a Destination Vector protocol; the data it carries are routing table entries. It detects and prevents routing loops by tagging each table entry with the complete path; this variant of DV is called Path Vector.