A function that prevents a router from being updated for a specified period in order to give other nodes some time to reconfigure and prevent a routing loop. When a router is notified of a route failure, it starts the holddown timer. In the meantime, if a notification of a route is received from its neighbor with equal or better metrics than the route that failed, the router stops the timer and updates its routing table. If the new route metrics are inferior, it keeps the timer running and does not update. See routing loop and route poisoning.