Routing Information Protocol (RIP)

RIP is one of the most commonly used routing protocol. It is a type of Interior Gateway Protocol used to dynamically adapting to changes on the network and communicating information about the other routers which can be reached by each router.

RIP is a distance-vector routing protocol employing the hop count as a routing metric. The maximum number of hops allowed with RIP is 15. The default update interval of RIP configured router is 30 seconds which results in large amount of network traffic. RIP runs above the network layer and uses UDP port 520 to transmit its updates. To avoid routing loops a technique called Split Horizon with Poison Reverse is used.

There are two version of RIP, RIPv1 and RIPv2.

RIPv1 uses classful routing and does not support VLSM (Variable Length Subnet Mask). This means that the internal subnets within the same network must be of same size and lack of authentication does not make it the first choice for networks.

RIPv2 was developed to overcome the limitations imposed by RIPv1 and as a result of new development, the RIPv2 supported classless Inter-Domain routing. But the limitation of 15 hop count still remained.