Which of the following statements is/are INCORRECT about the OSPF (Open…
2023
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.
Attempted by 173 students.
Show answer & explanation
Correct answer: A, C
Incorrect statements: "OSPF implements Bellman-Ford algorithm to find shortest paths." and "OSPF is used as an inter-domain routing protocol."
Why the first is incorrect: OSPF is a link-state protocol. Routers exchange link-state advertisements (LSAs) and each router runs Dijkstra’s shortest-path algorithm to compute the least-cost paths, not Bellman-Ford.
Why the second is incorrect: OSPF is an Interior Gateway Protocol (IGP) used within an Autonomous System (intra-domain). Inter-domain routing between Autonomous Systems is performed by BGP.
Why the other statements are correct: OSPF uses Dijkstra’s algorithm to compute shortest paths, and OSPF supports hierarchical routing by dividing the network into areas (including backbone area 0) to improve scalability.