RIP
acronymnetworking
Stands for: Routing Information Protocol
Routing Information Protocol - the internet's first common routing protocol: hop count as the metric, 15 hops as the horizon, and 'routing by rumor' as the method.
RIP (RFC 1058, refined as RIPv2 in RFC 2453) is pure distance-vector: every 30 seconds each router tells its neighbors the distances it believes, and everyone trusts the rumors. Hop count is the only metric - a 10 Gb/s link counts the same as a modem - and 16 means unreachable, which caps any RIP network at 15 hops and gives the count-to-infinity failure its ceiling. Split horizon, poison reverse, and hold-down timers are the folk remedies every networking student memorizes. Obsolete in serious networks, immortal in teaching: RIP is where the problems that OSPF and EIGRP solve are first felt.
RIP is the oldest interior routing protocol still encountered, using hop count as its only metric and capping at fifteen hops so that a loop terminates. It is simple enough to configure without understanding it, which is both its appeal and its problem.
Its limitations are structural. Hop count ignores bandwidth entirely, so a route over three fast links loses to one over two slow ones, and its convergence is slow enough that the workarounds carry names like split horizon and poison reverse. It survives in small networks and in equipment too old to run anything else, and encountering it in a modern environment is usually a signal that a segment has not been reviewed in a long time.
Also known as: rip