Poison reverse: A router learns from its neighbor that a route is down and the router sends an update back to the neighbor with an infinite metric to that route
LSA: The packets flooded when a topology change occurs, causing network routers to update their topological databases and recalculate routes
Split horizon: This prevents sending information about a route back out the same interface that originally learned about the route
hold down timer: For a given period, this causes the router to ignore any updates with poorer metrics to a lost network