RIP Timers

RIP uses several timers to manage its routing updates and ensure network stability:

• Update Timer (30 seconds): How often a router sends its complete routing table to its neighbors.
• Invalid Timer (180 seconds): If a router doesn't receive an update for a route within this time, the route is marked as invalid (hop count set to 16, unreachable).
• Holddown Timer (180 seconds): After a route is marked invalid, it enters a holddown state. During this time, the router will not accept any new updates for that route from other neighbors, preventing routing loops.
• Flush Timer (240 seconds): After a route is marked invalid, it remains in the routing table for this duration. Once the flush timer expires, the route is removed from the routing table.

These timers work together to ensure that routing information is propagated and converged correctly within the RIP domain, while also preventing routing loops.