Reference Guide

Routing Information Protocol (RIP) | 783

Routing Information Protocol (RIP)

Routing Information Protocol (RIP) is supported only on platforms: e c s

RIP is supported on the S-Series following the release of FTOS version 7.8.1.0, and on the C-Series with

FTOS versions 7.6.1.0 and after.

Routing Information Protocol (RIP) is based on a distance-vector algorithm, it tracks distances or hop

counts to nearby routers when establishing network connections.

• Protocol Overview on page 783

• Implementation Information on page 784

• Configuration Information on page 784

• RIP Configuration Example on page 792

RIP protocol standards are listed in the Chapter 56, Standards Compliance chapter.

Protocol Overview

RIP is the oldest interior gateway protocol. There are two versions of RIP: RIP version 1 (RIPv1) and RIP

version 2 (RIPv2). These versions are documented in RFCs 1058 and 2453.

RIPv1

RIPv1 learns where nodes in a network are located by automatically constructing a routing data table. The

routing table is established after RIP sends out one or more broadcast signals to all adjacent nodes in a

network. Hop counts of these signals are tracked and entered into the routing table, which defines where

nodes in the network are located.

The information that is used to update the routing table is sent as either a request or response message. In

RIPv1, automatic updates to the routing table are performed as either one-time requests or periodic

responses (every 30 seconds). RIP transports its responses or requests by means of UDP over port 520.

RIP must receive regular routing updates to maintain a correct routing table. Response messages

containing a router’s full routing table are transmitted every 30 seconds. If a router does not send an update

within a certain amount of time, the hop count to that route is changed to unreachable (a route hop metric

of 16 hops). Another timer sets the amount of time before the unreachable routes are removed from the

routing table.

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