Routing Information Protocol (RIP) is a distance-vector routing protocol intended for small, relatively homogeneous networks. Its widespread use started when an early version of RIP was included with BSD v4.3 Linux as the routed daemon. The routing algorithm used by RIP, the Bellman–Ford algorithm, first saw widespread use as the initial routing algorithm of the ARPANET.

RIP benefits include being well suited to smaller networks, is in widespread use, near universal support on routing hardware, quick to configure, and works well if there are no redundant paths. However, RIP updates are sent out node-by-node so it can be slow to find a path around network outages. RIP also lacks good authentication, can not choose routes based on different quality of service methods, and can create network loops if you are not careful.

The FortiGate implementation of RIP supports RIP version 1 (see RFC 1058), RIP version 2 (see RFC 2453), and the IPv6 version RIPng (see RFC 2080).