What is Routing Information Protocol (RIP)?

Have you ever imagined how you can access the servers in America from India? How are they connected? Our systems are connected to the routers which in turn are connected to many other routers which eventually are connected to the servers. So whenever we want to access any server, the link between our computer and server is established only through these routers. But how the routers are selected so that the distance between our computer and the server is minimal? This is what Routing Information Protocol (RIP) does. It selects the shortest path between the computer and the remote server. Now, let’s get down to the nitty and gritty of the RIP and discuss it in more detail.

What is Routing Information Protocol (RIP)?

Routing Information Protocol (RIP) is a distance vector protocol that uses hop count as its primary metric. RIP defines how routers should share information when moving traffic among an interconnected group of local area networks.

In the enterprise, Open Shortest Path First (OSPF) routing has largely replaced RIP as the most widely used Interior Gateway Protocol. RIP has been supplanted mainly due to its simplicity and inability to scale to very large and complex networks. In contrast, the Border Gateway Protocol (BGP) is a path vector routing protocol that is now used to transfer routing information across autonomous systems on the internet.

RIP was originally designed for Xerox PARC Universal Protocol and was called GWINFO in the Xerox Network Systems protocol suite in 1981. RIP, which was defined in RFC 1058 in 1988, is known for being easy to configure and easy to use in small networks.

How does it work?

In order to choose which path to place a packet on to reach its destination, the Routing Information Protocol uses a distance vector method. A routing table, or a list of all the locations the router is capable of reaching, is kept by each RIP router. Every 30 seconds, each router broadcasts its whole routing table to the closest neighbors.

The other routers to which a router is directly connected in this sense are the other routers that are on the same network segments as the chosen router. Up until all RIP hosts inside the network are aware of the same routing paths, the neighbors send the information to their closest neighbors in turn. This shared knowledge is called convergence.

A router will update its table entry with the length and next-hop address of the shorter path if it receives an update on a route and the new path is shorter. If the new path is longer, it will wait for a “hold-down” period to check if subsequent updates also include the longer path. If the new, lengthier path is found to be stable, it will just update the table entry.

The network learns about a router crash or broken network connection when the affected router stops delivering updates to its neighbors or ceases sending and receiving updates across the broken connection. A RIP router will remove a particular route and notify the rest of the network of the issue through its own periodic updates if the routing database for that route isn’t updated six times in a row (or for 180 seconds).

Features of Routing Information Protocol

Here are some features of the Routing Information Protocol:

• The network exchanges updates on a regular basis.
• Routing information updates are sent continuously.
• Updates include full routing tables.
• Routers always trust routing data obtained from neighbor routers. It’s also referred to as “routing on rumors.”

What are the different versions of RIP in networking?

There are three versions of the Routing Information Protocol in Networking. These are:

• RIPv1
• RIPv2
• RIPng (RIP Next Generation)

RIPv1:

• Version 1 of the RIP is a very old protocol.
• This version is not recommended to use while using the RIP.
• It only advertises classful addresses such as Class A, Class B, and Class C.
• Therefore, it does not support VLSM and CIDR.
• When RIPv1 advertises a network to a neighbor, it does not even include subnet mask information in advertisements.
• It is suitable for IPv4.
• The messages of version 1 are broadcasted to the IP address 255.255.255.255.
• Since IPv4 address classes are no longer in use, they are replaced with CIDR and VLSM.

RIPv2:

• It is not classful like version 1.
• It supports both CIDR and VLSM.
• It includes subnet mask information in its route advertisements to support it.
• For example, a /30 network will be advertised as /30.
• It supports IPv4.
• The messages are multicast to the IP address 224.0.0.9.

Note: Broadcast messages are delivered to all the devices in a local network. On the other hand, multicast messages are only sent to those devices that have joined the specific multicast group.

RIPng:

• It is a next-generation RIP.
• It is used in IPv6.

Advantages of Routing Information Protocol

• Simplicity: RIP is a relatively simple protocol to configure and manage, making it an ideal choice for small to medium-sized networks with limited resources.
• Easy implementation: RIP is easy to implement, as it does not require much technical expertise to set up and maintain.
• Convergence: RIP is known for its fast convergence time, meaning that it can quickly adapt to changes in network topology and route packets efficiently.
• Automatic updates: RIP automatically updates routing tables at regular intervals, ensuring that the most up-to-date information is being used to route packets.
• Low bandwidth overhead: RIP uses a relatively low amount of bandwidth to exchange routing information, making it an ideal choice for networks with limited bandwidth.
• Compatibility: RIP is compatible with many different types of routers and network devices, making it easy to integrate into existing networks.

Disadvantages of Routing Information Protocol

Unfortunately, the disadvantage of Routing Information Protocol is its increased network and processing overhead when compared to static routing.

Other disadvantages of RIP include the following:

• Not always loop-free.
• Only supports equal-cost load balancing.
• Pinhole congestion can occur.
• Bandwidth-intensive and inefficient.
• Large networks lead to slow convergence.

Conclusion

In conclusion, RIP is a dynamic distance-vector routing protocol that operates at the network layer of the OSI model. It primarily serves small networks by enabling routers to automatically discover and maintain routes, simplifying network management, and adapting to changes in topology. The protocol relies on hop count as its metric and utilizes techniques like split horizon and poison reverse to prevent routing loops.