Exterior Gateway Protocol
Encyclopedia
The Exterior Gateway Protocol (EGP) is a now obsolete routing protocol
for the Internet
originally specified in 1982 by Eric C. Rosen of Bolt, Beranek and Newman, and David L. Mills
. It was first described in RFC 827 and formally specified in RFC 904 (1984). Not to be confused with EGPs in general (of which EGP and Border Gateway Protocol
(BGP) are examples), EGP is a simple reachability protocol, and, unlike modern distance-vector and path-vector protocols, it is limited to tree-like topologies.
During the early days of the Internet, EGP version 3 (EGP3) was used to interconnect autonomous systems
. Currently, BGP version 4 is the accepted standard for Internet routing and has essentially replaced the more limited EGP3.
Routing protocol
A routing protocol is a protocol that specifies how routers communicate with each other, disseminating information that enables them to select routes between any two nodes on a computer network, the choice of the route being done by routing algorithms. Each router has a priori knowledge only of...
for the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
originally specified in 1982 by Eric C. Rosen of Bolt, Beranek and Newman, and David L. Mills
David L. Mills
David L. Mills is an American computer engineer and Internet pioneer. Mills earned his PhD in Computer and Communication Sciences from the University of Michigan in 1971...
. It was first described in RFC 827 and formally specified in RFC 904 (1984). Not to be confused with EGPs in general (of which EGP and Border Gateway Protocol
Border Gateway Protocol
The Border Gateway Protocol is the protocol backing the core routing decisions on the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems . It is described as a path vector protocol...
(BGP) are examples), EGP is a simple reachability protocol, and, unlike modern distance-vector and path-vector protocols, it is limited to tree-like topologies.
During the early days of the Internet, EGP version 3 (EGP3) was used to interconnect autonomous systems
Autonomous system (Internet)
Within the Internet, an Autonomous System is a collection of connected Internet Protocol routing prefixes under the control of one or more network operators that presents a common, clearly defined routing policy to the Internet....
. Currently, BGP version 4 is the accepted standard for Internet routing and has essentially replaced the more limited EGP3.
External links
- TCP/IP Exterior Gateway Protocol (EGP) EGP Overview by The TCP/IP Guide