Link state routing protocols, such as OSPF, do require that each router maintains a complete topology map of the network. This is achieved by having routers distribute and update this information amongst themselves. Each router then independently calculates the best path to each network segment, resulting in a complete view of the network's topology. In contrast, distance vector routing protocols do not require a router to have a complete topology map, as they rely on neighboring routers to inform them of the topology beyond their immediate network.