Which statement accurately describes link-state routing protocols?

• A. They rely on periodic updates of full routing tables to neighbors.
• B. They build a complete topology map and flood link-state advertisements.
• C. They flood all router configurations to the network.
• D. They ignore topology changes.

Answer: (B)

Link-state routing protocols work by each router discovering the state of every link in the network and sharing that information with all routers in the area. Each router advertises its directly connected links in link-state advertisements and floods these messages to every other router in the area. With those flooded messages, every router builds a complete topology map of the network, then runs a shortest-path algorithm (typically Dijkstra) to compute the best path to every destination. Because every router uses the same topology view, they converge quickly when a change occurs. When a link changes, the router detects it and floods new LSAs to update everyone’s view, rather than periodically sending full routing tables. Routers don’t flood configurations; they flood link-state information to maintain an up-to-date network map.