ROUTING PROTOCOL

A routing protocol is a mechanism embedded into a router to specify how routers communicate with each other, distributing information that enables them to select routes between any two nodes on a computer network.

The function of router on any network is to direct traffic. Data packet are forwarded through the networks of the internet from router to router until they reach their destination computer.

Routing can be seen as algorithm which determine the specific choice of route. Each router has a prior knowledge only of networks attached directly to it. A routing information distributes information about all the networks attached to it among the neighbors and then throughout the network. This way, routers gain knowledge of the topology of the network. The ability of routing protocols to dynamically adjust to changing conditions such as disable data lines and computers and route data around obstructions is what gives the internet its survivability and reliability.

The specific characteristics of routing protocols are;

1. The ways they avoid routing loops


2. The ways they select preferred routes


3. The ways they use information about hop costs


4. The time it require to reach routing convergence


5. The scalability e.t.c

TYPES

There are many types of routing protocols usable around the world, but they are classified into three main part

1. Interior gateway Protocol type 1


2. Interior Gateway Protocol type 2


3. Exterior Gateway Protocols

Interior Gateway Protocol Type 1

This is a Link-state routing protocols which are one of the two main classes of routing protocols used in packet switching networks for computer communications.

Examples of link-state routing protocols are

*          Open Shortest Path First (OSPF)

*          Intermediate System to Intermediate System (IS-IS).

Interior Gateway Protocol Type 2

This is a distance-vector routing protocol in data networks which determines the best route for data packets based on distance. Distance-vector routing protocols measure the distance by the number of routers a packet has to pass, one router counts as one hop. Some distance-vector protocols also take into account network latency and other factors that influence traffic on a given route.

Examples are;

*          Routing Information Protocol

*          Routing Information Protocol Version 2 (RIPv2)

*          Interior Gateway Routing Protocol (IGRP)

Exterior Gateway Protocols

This is a routing protocol used to exchange routing information between autonomous systems. This exchange is crucial for communications across the Internet.

Examples are;

*          Border Gateway Protocol (BGP)

*          Path Vector Routing Protocol

SOFTWARES FOR ROUTING PROTOCOLS

There are many software implementations exists for most of the common routing protocols.

Examples are;

*          Bird Internet routing daemon

*          Quagga

*          GNU Zebra

*          OpenBGPD

*          OpenOSPFD

*          XORP