What is an example of an exterior gateway protocol (EGP)?

An example of an exterior gateway protocol (EGP) is BGP (Border Gateway Protocol). BGP is specifically designed to exchange routing information between different autonomous systems (AS) on the Internet, making it the de facto standard for Internet routing. It helps in determining the best paths for data transmission across the diverse networks that exist globally.

BGP's ability to handle a vast and complex interconnection of networks is essential for maintaining the stability and efficiency of Internet routing. Unlike interior gateway protocols (IGPs), which operate within a single AS, BGP focuses on routing between multiple ASes, allowing it to manage and optimize the routing decisions for large-scale environments. Its use of path vector technology and policy-based routing attributes further enhances its role in EGP.

The other protocols mentioned—OSPF, EIGRP, and RIP—are categorized as interior gateway protocols (IGPs), which are aimed at routing within a single AS rather than between multiple ones. This distinction reinforces why BGP is recognized as an EGP, playing a critical role in the global network architecture.