3-13 RIP ConfigurationWhen configuring RIP, go to these sections for information you are interested in:z RIP Overviewz RIP Configuration Task Listz RIP Configuration Examplez Troubleshooting RIP ConfigurationThe term router in this chapter refers to a router in a generic sense or an Ethernet switch running arouting protocol.RIP OverviewRouting information protocol (RIP) is a simple interior gateway protocol (IGP) suitable for small-sizednetworks. RIP is not recommended in complicated large networks.Basic ConceptsRIPRIP is a distance-vector (D-V) algorithm–based protocol. It uses port 520 to exchange routinginformation through UDP packets.RIP uses hop count (also called routing cost) to measure the distance to a destination address. In RIP,the hop count from a router to its directly connected network is 0, and that to a network which can bereached through another router is 1, and so on. To restrict the time to converge, RIP prescribes that thecost is an integer ranging from 0 and 15. The hop count equal to or exceeding 16 is defined as infinite;that is, the destination network or host is unreachable. This limitation makes RIP not suitable for largenetworks.To improve performance and avoid routing loop, RIP supports split horizon. Besides, RIP can importroutes discovered by other routing protocols.RIP routing databaseEach RIP router has a routing table containing routing entries of all reachable destinations, and eachrouting entry contains:z Destination address: IP address of a host or network.z Next hop: IP address of an interface on the adjacent router that IP packets should pass through toreach the destination.
