Distance vector and Link state protocols

• Distance vector protocols (RIP, RIPv2, IGRP): find the best path to a remote network based on distance. Every time a packet goes through a router we have a hop and the best route will be the shortest one, i.e. the one having the fewest hops. These protocols send the whole routing table to all directly connected neighbors.
• Link state protocols or shortest path first protocols (OSPF, IS – IS): if the router is set up according to them it creates three separate tables: one keeping track of directly attached neighbors (neighbor table), one determining the topology of the whole internetwork (topology table) and one forming the actual routing table. Link state protocols know more about the internetwork than distance vectors protocols, as they update routers about the state of their own links.