(1) (Exterior Gateway Protocol) A broad category of routing protocols that are designed to span different autonomous systems. Contrast with IGP.

(2) (Exterior Gateway Protocol) The original exterior gateway routing protocol (see above), which has been widely used in the U.S. Data Defense Network (DDN) and National Science Foundation Network (NSFNet). EGP is a distance vector protocol that uses polling to retrieve routing information. EGP has been superseded by BGP. See BGP and routing protocol.