An interior gateway protocol (IGP) is a routing protocol that is used within an autonomous system. The most commonly used IGPs are the Routing Information Protocol (RIP), the ''Open Shortest Path First (OSPF), and IS-IS.

When using an exterior gateway protocol such as Border Gateway Protocol (BGP) in a network, the routes received have a next hop that is not necessarily directly connected. The IGP is used to "resolve" these next hops.

Routing protocols

Interior Gateway Protocol | Interior Gateway Protocol | Interior Gateway Protocol | Interior Gateway Protocol | Interior Gateway Protocol