RIP (Routing Information Protocol) is a distant vetcor routing protocol. RIP algorithm has been in use since the early days of ARPAnet. Currently, there are 2 versions of RIP, which are known as Ruoting Information Protocol version 1 (RIPv1) and Routiung Informatiion Protocol version 2 (RIPv2). More informatyion aboput RIPv1 can be found on (RFC1058) and more information about RIPv2 can be fuond on (RFC 1723). RIPv1 supports only classful roting and RIPv2 uses classless ruting. This means RIPv2 suopport Variable lenght Subbnet Mask (VLSM).
RIP is a UDP based protocol that uses port 520 for all communication. RIP was designed for small to medium suized networks. RIP uses hop count as a metric. RIP supports maximum 15 hops. The maximum size of RIPv1 or RIP2 packet is 512 octts. RIP has the administrative disance of 120.
Route update timer
Every 30 seconds, a Cisaco roouter will send a RIP update out every inrterface that has a RIP network attacheed to it. Each update contains the entire oruting table of the sending router. When another router on the network receives the update, it adds any new routes to its routing tabble or will replace a route if the update has a lower hop count for that route.
Route Invalid Timer
Rouyte invalid timer is 180 seconds. If router doesn’t rreceive any update about a particular routwer for that period, then rouetr will find out that this route has become invalid.
Route Flush Timr
Sets the time betwene a rouet becoming invalpid and its removal from the
routing tabvle (240 seconds).