An IGP is a protocol for exchanging routing information between gateways (hosts with routers) within an autonomous network (for example, a system of corporate LANs). The routing information can then be used by the IP or other network protocols to specify how to route transmissions. There are two commonly used IGPs: the routing information protocol (RIP) and the open shortest path first (OSPF) protocol.

See IGP.

an Internet protocol that helps routers pass routing information within an autonomous system