Multiple choice

Refer to the exhibit. Router1 and Router2 are running OSPF. The show ip ospf neighbor command reveals no neighbors. What is a possible cause?

  1. OSPF autonomous system IDs do not match.

  2. OSPF process IDs do not match.

  3. OSPF network types are identical.

  4. OSPF hello or dead timers do not match.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

OSPF neighbors must have matching hello and dead timer intervals to form adjacencies. These timers determine how often OSPF sends hello packets and when a neighbor is declared down. Mismatched timers prevent neighbor discovery even if other parameters match. OSPF process IDs are local to each router and don't need to match. Autonomous system IDs are used in BGP, not OSPF. Identical network types would actually help OSPF work, not prevent it.

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