Which of the following statements is/are INCORRECT about the OSPF (Open Shortest Path First) routing protocol used in the Internet?

A.

OSPF implements Bellman-Ford algorithm to find shortest paths.

B.

OSPF uses Dijkstra’s shortest path algorithm to implement least-cost path routing

C.

OSPF is used as an inter-domain routing protocol. 

D.

OSPF implements hierarchical routing.

Solution:

OSPF uses Dijkastra’s shortest path algorithm to implement least-cost path routing.

OSPF (Open Shortest Path First) is primarily an intra-domain (interior gateway) routing protocol, not an interdomain (exterior gateway) routing protocol. OSPF is designed to be used within an autonomous system (AS) to determine the shortest path between routers within that AS. It operates within a single administrative domain and is used for routing within that domain.

OSPF implements Hierarchical routing.

So, options A and C are incorrect.