RIP is a dynamic, distance vector routing protocol based around the Berkely BSD application routed and was developed for smaller IP based networks. RIP uses UDP port 520 for route updates. RIP calculates the best route based on hop count. Like all distance vector routing protocols, RIP takes some time to converge. While RIP requires less CPU power and RAM than some other routing protocols, RIP does have some limitations:
Since RIP calculates the best route to a destination based solely on how many hops it is to the destination network, RIP tends to be inefficient in network using more than one LAN protocol, such as Fast Ethernet and serial or Token Ring. This is because RIP prefers paths with the shortest hop count. The path with the shortest hop count might be over the slowest link in the network.
RIP cannot handle more than 15 hops. Anything more than 15 hops away is considered unreachable by RIP. This fact is used by RIP to prevent routing loops.
RIP is a classful routing protocol. RIP cannot handle classless routing. RIP v1 advertises all networks it knows as classful networks, so it is impossible to subnet a network properly via VLSM if you are running RIP v1, which
RIP ROUTING UPDATES
Routers running IP RIP broadcast the full list of all the routes they know every 30 seconds. When a router running RIP hears a broadcast it runs the distance vector algorithm to create a list of best routes.
BASIC RIP CONFIGURATION (Cisco)
router# conf t
router(config)#interface ethernet 0
router(config-if)# ip address 192.168.42.1
router(config-if)# interface ethernet 1
router(config-if)# ip address 192.168.43.1
router(config-router)# network 192.168.42.0
router(config-router)# network 192.168.43.0
The example above assumes that the interfaces that will be running RIP have IP addresses on them that fall within the 188.8.131.52, and 184.108.40.206 class C ranges