BGP - Border Gateway Protocol
BGP represents an attempt to address the most serious of EGP's problems. Like EGP, BGP is an inter-domain routing protocol created for use in the Internet core routers.
BGP was designed to detect routing loops and to use a metric so that intelligent routing decisions may be made (BGP is the next-generation EGP, BGP is replacing EGP in the Internet )
BGP is specified in RFC 1163