RIP Versus OSPF and IS-IS

The distinction between RIP and the OSPF and IS-IS link-state protocols lies in the fundamental differences between distance-vector protocols and link-state protocols.

Using a distance-vector protocol, each router creates a unique routing table from summarized information obtained from neighboring routers. Using a link-state protocol, every router maintains an identical routing table created from information obtained from all routers in the autonomous system (AS). Each router builds a shortest path tree, using itself as the root. The link-state protocol ensures that updates sent to neighboring routers are acknowledged by the neighbors, verifying that all routers have a consistent network map.