Description: The Exterior Gateway Protocol (EGP) is a routing protocol designed to facilitate the exchange of routing information between different autonomous systems (AS). An autonomous system is a set of IP networks and routers under the control of a single administrative entity that presents a common routing policy. EGP allows these autonomous systems to communicate with each other, providing a structured way to share information about the accessibility of networks and available routes. This protocol is fundamental for the interconnection of large-scale networks, such as those that make up the Internet, as it enables routers from different administrations to exchange information efficiently. Through EGP, routers can learn about routes to other networks and make informed decisions on how to route data traffic. Although EGP has largely been replaced by more advanced protocols, particularly the Border Gateway Protocol (BGP), its design and principles laid the groundwork for the development of these more sophisticated protocols, which are essential for the functioning of the Internet today.
History: The Exterior Gateway Protocol (EGP) was developed in the 1980s as part of efforts to establish a standard protocol for routing between different autonomous systems. EGP was one of the first protocols used for routing between networks, but with the growth of the Internet and the need for a more robust and scalable protocol, it was eventually replaced by the Border Gateway Protocol (BGP) in 1994.
Uses: EGP was primarily used for exchanging routing information between autonomous systems on early packet-switched networks and in the initial phases of the Internet. Although it has since been replaced by BGP, its initial design helped lay the groundwork for routing between different networks and systems.
Examples: An example of EGP usage can be seen in the early interconnections of academic and governmental networks in the United States, where it was used to facilitate communication between different universities and research centers.
