Routing Information Protocol Concept
Routing Information Protocol (RIP) is a true distance-vector routing protocol based on Belman Ford algorithm. RIP sends the complete routing table out to all active interfaces every 10 seconds.
RIP only uses hop count as metric, to determine the best way to a remote network, but it has a maximum allowable hop count of 15 by default, meaning that 16 is deemed unreachable.
It works well in small networks, but it’s inefficient on large networks with slow WAN links or on networks with a large number of routers installed.
RIP version 1 supports only classful routing, which means that all devices in the network must use the same standard subnet mask.
This is because RIP version 1 doesn’t send updates with subnet mask information in tow.
RIP version 2 provides something called prefix routing and does send subnet mask information with the route updates. This is called classless inter-domain routing (CIDR).
RIP uses four different kinds of timers to regulate its performance:
Route update timer Sets the interval (typically 10 seconds) between periodic routing updates in which the router sends a complete copy of its routing table out to all neighbors.
Route Timeout timer Determines the length of time that must elapse (120 seconds) before a router determines that a route has become invalid.
Route Garbage timer Sets the time between a route becoming invalid and its removal from the routing table (60 seconds). Before it’s removed from the table, the router notifies its neighbors of that route’s impending demise.
--MikroTik Certified Trainer 16:18, 12 April 2013 (UTC)