Some routers avoid the entire issue of path-finding by relying either on a human or host computer to make these decisions. In the former case, the network manager provides each router with a block of static routing configuration information at start-up, including the information needed to make routing decisions. In the host-router implementation, end hosts place information in every packet they place on the network. This information indicates every path and the immediate router the data must pass through to get to its destination. This is source-routing .
More complex networks require dynamic routing solutions.
In large wide area networks with multiple links between networks, routers perform more efficiently when they understand how the network is linked together. An integrated router does this by exchanging information about the network's topology with other integrated routers. As a result of this exchange, integrated routers create routing tables that show the best paths between the various links on the internet. Algorithms for integrated routers must be able to quickly determine the network topology. This process, called convergence, must take place rapidly, otherwise routers with obsolete or incorrect data about the network can send data into dead-end networks or across unnecessary links.