IS-IS

IS-IS is a routing protocol used in computer networks. It is used to exchange routing information between routers in a network. IS-IS is a link-state routing protocol, which means that each router in the network maintains a database of the entire network topology. This database is then used to calculate the best path for data to travel from one router to another. IS-IS is used in large networks, such as those used by ISPs, and is also used in some large corporate networks. IS-IS is an open standard, meaning that it is not proprietary and can be used by any vendor. IS-IS is also used in some parts of the Internet, such as in the Border Gateway Protocol (BGP).