The next-hop router for network 192.168.3.0 has changed. We need to make the change with the least amount of effort possible. And hence, we should wait for the convergence to take place. We need to understand that when a change happens in the network topology, the routing table gets updated, And this information exchange happens not till all the routers get updated, and that is their routing tables to reflect the nascent network topology. And this process of routing tables updating on change in the network topology is known as the convergence. And hence, we should wait for the convergence to take place.
