RIP: Routing Information Protocol

Introduction

RIP is one of the oldest routing protocols in the history of networks. The RIP protocol uses a distance vector algorithm which helps in determining which path a packet (data) should take in order to reach its destination. Each router maintains a routing table which lists all the paths that the router should know to deliver the packets. This routing table gets updated by routers at regular intervals of time by broadcasting its whole table to its neighbour routers. Typically every 30 seconds, RIP routers update their routing tables.

What is RIP

Routing Information Protocol'' (RIP) is a distance-vector protocol which uses hop count as its primary metric. It governs the router and directs them to share information with the neighbouring routers connected to the local area network. In order to prevent

routing loops, RIP implements the maximum number of hops allowed in a path from source to destination. The hop count can be defined as the number of routers between the source and destination. The maximum number of hops allowed in a RIP network is 15 which limits RIP to small networks only (local area network). The hop count of 16 indicates that the network is unreachable.

RIP protocol runs with an Administrative Distance (AD) of 120 and port 520 on the OSI model of network layer.

• Command − It is used for request and response. It is an 8-bit field. The request is represented by 1 whereas the response is represented by 2

• Version − Version represents the protocol version of RIP in use. Let’s assume we use version 1 of the protocol, then we enter 1 in this field

• Reserved − It is a reserved filed and it's represented by 0

• Family − This is a 16-bit field. Since we use TCP/IP protocol, we put 2 in this field

• Network − Address: It's a 14 byte field. Since we use IPv4 which gets filled in 4 bytes, rest 10 bytes remain zero

• Distance − The hope count or the total number of routers require to reach the destination network is represented by this field

Following are the benefits of RIP

• Easy to understand

• Feasible to configure

• Supported by all the routers

• Support load balancing

Additionally, RIP is preferred over static routing due to the fact that it doesn't require manual updates when the topology changes and it’s simple to configure.

There are in total 3 versions of RIP

• RIPv1

• RIPv2

• RIPng

History of RIP

In 1981, Routing Information Protocol (RIP) was first developed by GWINFO in the Xerox Network System protocol suite for Xerox PARC Universal Protocol. However, RIP was first mentioned in RFC 1058 in 1988. Since its inception, RIP has the reputation for being simple to set up and easy to use for small networks.

Limitation of RIP

The followings are the limitations/disadvantages of RIP

• Increased processing overheads when compared to static routing

• Not always loop-free

• Not so cost-effective in load balancing

• Pinhole congestion can occur

• Require large bandwidth

• Not suitable for the larger network as this leads to slow convergence

• Due to periodic checks on the routing table of neighbouring routers every 30 seconds, RIP tends to increase network traffic

• It only updates neighbouring routers, hence non-neighbouring routing updates can be forgotten since the information is not accessible immediately

• RIP enforces a maximum hop count limit as this restricts the usability of RIP to local networks only

• The shortest path is also not always guaranteed

Implementation of RIP

The Routing Information Protocol (RIP) is used by almost all Original Equipment Manufacturers (OEMs) of networks. Following are the past and current applications of RIP −

• Cisco IOS (software used in Cisco Routers) and Cisco NX-OS (Cisco Data Center Switches) support RIP

• Junos (Juniper software) used in Juniper Routers, Switches and Firewalls support RIP

• The remote access feature of Windows Server supports RIP

• Some open-source software such as BIRD, Quagga, ZeroShell, etc.

• Netgear and Huawei routers also support RIP

Use of RIP

Routing Information Protocol (RIP) is used to transfer data packets from source to destination computer through the network with the help of routers.

These are the set of guidelines designed by computer scientists for an easy and effective way to connect through the connection of routers. The following are the usefulness of Routing Information Protocol (RIP) −

• It is a fundamental protocol to connect users on the world wide web

• This helps easy and automatic configuration of routers among each other

• It helps with periodic network updates

• It helps routers on finding an effective path to establish communication between source and destination routers

Conclusion

RIP (Routing Information Protocol) is a set of rules which governs how data packets are transferred from source to destination with the help of a distance vector algorithm. This protocol helps routers in identifying the optimum path with the help of hop count which sets a maximum limit of 15 routers between source and destination. If a network requires more than 15 hops, it will be considered an inaccessible network by the routers in RIP. Hence it's suitable for small networks only.

RIP is supported by almost all routers as this is considered to be the easiest among all routing protocols due to its ease in configuration and routing table auto-update feature. However, sending routing updates to all the routers generates unnecessary network traffic.

FAQS

What is the difference between RIP and OSPF?

Unlike RIP, which requires routers to send routing table updates every 30 seconds, whereas OSPF (open shortest path first) sends the updated part of the routing table only when a change has to occur.

What are the other types of a routing protocol?

Following are the other types of routing protocol (to name a few) &minus

• Interior Gateway Routing Protocol (IGRP)

• Open Shortest Path First (OSPF)

• Border Gateway Protocol (BGP)

• Exterior Gateway Protocol (EGP)

Q3. Is RIP a TCP and UDP?

RIP uses UDP (User Datagram Protocol) as the transport protocol.