Which network protocol is known for flooding its link-state advertisements to all routers to maintain a consistent network topology view?

• A. RIP (Distance Vector)
• B. OSPF (Link State)
• C. BGP
• D. ECMP

Answer: (B)

Link-state routing relies on each router building a complete map of the network by exchanging topology information with every other router in the area. This is done by flooding link-state advertisements so that all routers receive the same set of link descriptions and metrics, giving them identical views of the network.

OSPF operates this way: each router learns its directly connected links and their costs, creates LSAs describing those links, and floods those LSAs to every other router in the area. Because LSAs propagate everywhere, every router ends up with the same link-state database, which it uses to run a shortest-path-first calculation to determine the best routes. This approach yields fast convergence and a consistent topology view across the network.

In contrast, RIP uses a distance-vector approach, sharing routing tables with neighbors rather than flooding topology information. BGP is a path-vector protocol focused on exchanging path attributes between autonomous systems, not flooding a topology map. ECMP is not a routing protocol itself; it’s a method for distributing traffic across multiple equal-cost paths that may be used once routes are known.