Exterior Gateway Protocol

The Exterior Gateway Protocol was a routing protocol used in the TCP/IP protocol suite for providing the information needed for doing path selection between a connected group of Autonomous Systems, which was the first exterior gateway protocol.

It is now obsolete, and no longer in use. It was a Destination Vector protocol; the data it carried was routing table entries.

It did not have any mechanism for detecting and preventing routing loops; EGP was only intended for use in networks in which the graph of AS connectivity did not contain any cycles. The current EGP, BGP, does not have this limitation.