Route Poisoning and Counting to Infinity Problem

In distance vector routing protocols, a common problem known as the “counting to infinity” problem can occur. This occurs when a router receives information about a network from multiple sources and forwards this information to other routers. If one of the links in the network fails, the router may still believe that the network is reachable via another path, even though it is not. The router then continues to advertise this information to other routers, causing a loop of information and leading to a slow convergence time.

Route poisoning is a solution to this problem in distance vector routing protocols. When a router detects a failed link or network, it sends out a routing update that includes the failed route with an infinite metric, indicating that the route is no longer valid. The other routers then update their routing tables accordingly and stop forwarding traffic to the failed network.

By poisoning the route, routers can quickly converge and update their routing tables, preventing loops and reducing the overall convergence time.