It is an application layer protocol used to route data packets by finding the best Hop count. A fairly crude way of trying to determine the best path. Most of the newer protocols also look for the time it takes for the data Packet to get to the destination.
Some routers might become congested so even using the hop count sometimes might not be the best method.
RIP stands for Routing Information Protocol. It’s an older protocol using the hop count, Not the most efficient today because in some of these router there exist lot of congestion and congestion might slow the routers.
RIPv1 goes back a long time being the first routing protocol for writing the IP packets. It goes back into the 1970 and as a result it was very popular in the very early networks. The only disadvantage the RIPv1 had was that it use broadcast to advertise its neighbor.
The networks it knew about instead of using multicast. It also does not have the VLSM support, it did not support the variable length Subnet Mask. If we have a class full network and it was sub-netted at using different subnet mask length that was not supported.
The rip and trip version 1 was designed to route IPv4 networks.
Then in 1990 RIPv2 came out and it had some serious enhancement, instead of using broadcast to communicate with other RIP speaking routers it used multicast. Especially it sent round advertisement to a multicast address of 126.96.36.199.
It did support variable length subnet masking and like RIPv1 it also support IP version 4. During that time IPv6 was introduced and RIPv2 does not support it.
Rip version 3 is not known as RIPv3 but it is known as “RIP in G“. Which means RIP next generation. It also uses multicast but since we are in IPv6 networks. Instead of sending to a multicast of 188.8.131.52.
It sent to an IPv6 multicast address of FF02::9. It also have VLSM support. The basic difference is that it was designed for IPv6.
RIP can calculates a matrix as a hop count. How many routers do I have to transit? Do I have to hop through in order to get to the destination network? If it needs one router to get to a destination then, that network would have a hop count of 1.
The hop count of 16 is considered to be unreachable. That is considered to be an infinite hop count. So it can cross maximum 15 routers. In order to reach the destination network advertise via RIP and as a result RIP is not going to be a good choice for us if we need to scale to a very large scale enterprise network.
Another characteristic that is common to both of these RIP version is that they will send a trigger update. If there is a topology change in the network that a router knows about. But in addition to trigger update it is going to send the full update.
By default after every 30 second it is going to send to its neighbors its entire routing table. That’s the big reason RIP is not a suitable choice for large networks.