Routing loop prevention
RIP uses the following mechanisms to prevent routing loops:
Counting to infinity—A destination with a metric value of 16 is considered unreachable. When a routing loop occurs, the metric value of a route will increment to 16 to avoid endless looping.
Triggered updates—RIP immediately advertises triggered updates for topology changes to reduce the possibility of routing loops and to speed up convergence.
Split horizon—Disables RIP from sending routing information on the interface from which the information was learned to prevent routing loops and save bandwidth.
Poison reverse—Enables RIP to set the metric of routes received from a neighbor to 16 and sends these routes back to the neighbor so the neighbor can delete such information from its routing table to prevent routing loops.