Open Shortest Path First (OSPF) uses which type of routing algorithm?

Open Shortest Path First (OSPF) uses which type of routing algorithm?

• A. Link State
• B. Distance Vector
• C. Adaptive
• D. Path Vector

Answer: (A)

The main idea is that OSPF uses a link-state routing approach. In link-state, every router floods information about its directly connected links to all other routers in the area, so every router builds a complete map of the network topology. With that full view, each router runs a shortest-path algorithm (like Dijkstra) to determine the best path to every destination. This leads to fast convergence and consistent routing decisions within an area. Distance-vector routing, by contrast, relies on routers sharing their distance vectors with neighbors and updating routes based on those counts, which can be slower to converge and prone to certain issues. Path Vector is the approach used by BGP, not OSPF. Adaptive isn’t a standard routing algorithm term used for core routing protocols in this context. So, OSPF is best described as a link-state routing protocol.

The main idea is that OSPF uses a link-state routing approach. In link-state, every router floods information about its directly connected links to all other routers in the area, so every router builds a complete map of the network topology. With that full view, each router runs a shortest-path algorithm (like Dijkstra) to determine the best path to every destination. This leads to fast convergence and consistent routing decisions within an area.

Distance-vector routing, by contrast, relies on routers sharing their distance vectors with neighbors and updating routes based on those counts, which can be slower to converge and prone to certain issues. Path Vector is the approach used by BGP, not OSPF. Adaptive isn’t a standard routing algorithm term used for core routing protocols in this context.

So, OSPF is best described as a link-state routing protocol.