Small frequently issued packets Discover neighbours and negotiate "adjacencies" Verify continued availability of adjacent neighbours Hello packets and Link State Advertisements (LSAs) build and maintain the topological database Hello packets are addressed to . | Distance Vector Link State Hybrid Distance Vector vs. Link State Route table Topology Incremental Update Periodic Update Routing by rumor A B C D X E DV- the router D will tell C that I know network X, and C will tell B that I know network X and so on, route A does not know anything beyond its neighbor, so its routing by tumor. This also uses periodic update, it also sends the entire routing table, these protocls are based in the early days of internet and some of them are class based. Link state gives much more information, here the link is defined with its interface, IP address, Mask, the type of network its on and its neighbors SO Router A will tell My IP . This information is passed to router to router and maintain two databases. The topology table is important and its because of topology table the robustness comes. The topology table contains Link state advertisements and the router knows the network topology, any network fails the convergence is faster. Distance Vector vs. Link State Distance Vector Updates frequently Each router is "aware" only of its immediate neighbors Slow convergence Prone to routing loops Easy to configure Link State Updates are event triggered Each router is "aware" of all other routers in the "area" Fast convergence Less subject to routing loops More difficult to configure DV will send entire routing table will waste the bandwidth. Link states exchange updates about only Link states Suitable for very large networks Comparison Continued Distance Vector Fewer router resources required Updates require more bandwidth Does not "understand" the topology of the network Link State More router resource intensive Updates require less bandwidth Has detailed knowledge of distant networks and routers Link State Routing Link State Example OSPF IS-IS OSPF is used for corporate networks IS-IS is used for ISP’s OSPF Open Shortest Path First (OSPF) OSPF is an open standards routing protocol This works by using the Dijkstra . | Distance Vector Link State Hybrid Distance Vector vs. Link State Route table Topology Incremental Update Periodic Update Routing by rumor A B C D X E DV- the router D will tell C that I know network X, and C will tell B that I know network X and so on, route A does not know anything beyond its neighbor, so its routing by tumor. This also uses periodic update, it also sends the entire routing table, these protocls are based in the early days of internet and some of them are class based. Link state gives much more information, here the link is defined with its interface, IP address, Mask, the type of network its on and its neighbors SO Router A will tell My IP . This information is passed to router to router and maintain two databases. The topology table is important and its because of topology table the robustness comes. The topology table contains Link state advertisements and the router knows the network topology, any network fails the convergence is faster. Distance Vector vs. .
