Router Information Protocol

·      RIP is a distance vector protocol. Using RIP, each router sends its entire routing table to its closest neighbors every 30 seconds

·      The neighbors in turn will pass the information on to their nearest neighbors, and so on

·      If a router crashes or a network connection is severed, the network discovers this because that router stops sending updates to its neighbors, or stops sending and receiving updates along the severed connection

·      If a given route in the routing table isn't updated across six successive update cycles (that is, for 180 seconds) a RIP router will drop that route, letting the rest of the network know via its own updates about the problem and begin the process of reconverging on a new network topology.

Ø When router receives routing updates, it compares them with the routes which it already has in its routing table.

Ø If update has information about a route which is not available in its routing table, router will consider that route as a new route.

Ø Router will add all new routes in routing table before updating existing one.

Ø If update has better information for any existing route, router will replace old entry with new route.

Ø If update has exactly same information about any existing route, router will reset the timer for that entry in routing table.