A classful distance vector routing protocol that uses ticks and hop count as its metric. RIP was based on a Xerox protocol named GWINFO and a later modification called routed (pronounced "route-dee") was included with BSD in 1982. RIP is an IGP, so it routes in a single autonomous system.

RIP 2 allows more info to be included in the packets and has a simple authentication mechanism.

RFC 1723 updates RFC 1058.