Overview

RFC 1058, upon which the Routing Information Protocol (RIP) is based, tells us that " Routing is the task of finding a path from a sender to a desired destination." In fact, we should say that routing is the task of finding the best path from a sender to a destination, since multiple paths could and often do exist. The Routing Information Protocol then, provides us with one of a series of standardized protocols designed to make the task of routing adaptive. That is one where routers will respond to changes in network topology when they occur. When routing is adaptive in this way, a change in network topology detected by one router will be advertised to all other routers in the internet. In this way, operator intervention is reduced, and overall network uptime is increased.

RIP is designed to be used as what is called an Interior Gateway Protocol (IGP), a routing protocol that is used within an autonomous system (an internetwork controlled by a single administrative or technical authority). While the size of autonomous systems that use RIP must be modest (no more than 15 intervening networks between the source and the destination), RIP provides a robust protocol that has now become a de-facto standard for the exchange of routing information among routers and hosts. Where we wish to link these autonomous systems together, as in a nation-wide (or even global) network, these are then linked via Exterior Gateway Protocols (EGPs), such as the