Compare and contrast the advertisements used by RIP and OSPF?

Answer 1

RIP is limited ti 15 hops and OSPF is not.
OSPF calcualte the best path by many parameters like bandwidth, delay etc. whereas RIP works only on hop counting.

Answer 2

The fundamental difference between OSPF and RIP is that they are based on two different algorithms. OSPF is based on the Dijkstra link-state algorithm. RIP is based on the Bellman-Ford distance-vector algorithm. Using OSPF's link-state algorithm, every router maintains a similar network map identifying all links between neighbors. Best paths are calculated from these maps. OSPF also ensures that updates sent to neighboring routers are acknowledged by neighbors, verifying that all routers have consistent network maps. Using RIP's distance-vector algorithm, every router creates a unique routing table identifying the best path from itself to all other routers in the network.

Of the two protocols, OSPF's acknowledgment-oriented routing update process is far more responsive to changes in network topology. Routers can make decisions faster when their network information is known to be consistent with that of other routers.