300-440 Question 91
Single answerA network administrator is configuring an OSPF neighbor relationship between two routers, R1 and R2, over a point-to-point link. After completing the configuration, the neighbor relationship fails to establish. Upon investigation, the administrator discovers a mismatch in the authentication configuration. What should the administrator do to resolve the issue?
- A
Ensure both routers are using the same authentication type and key.
- B
Disable authentication on both routers.
- C
Configure each router to use a unique authentication key.
- D
Verify that the OSPF router IDs are identical on both routers.
Show answer and explanation
Correct answer: A
Explanation
To establish an OSPF neighbor relationship, both routers must be configured with the same authentication type and key. If there is a mismatch, the routers will not form a neighbor relationship. Ensuring consistent authentication parameters resolves the issue without compromising security.
- A. Correct.
Correct. OSPF neighbor relationships require both routers to use the same authentication type (e.g., none, plaintext, or MD5) and the exact same authentication key. A mismatch will prevent the neighbor relationship from forming.
- B. Incorrect.
Incorrect. Disabling authentication is not recommended in most production environments as it compromises the security of OSPF communications.
- C. Incorrect.
Incorrect. Both routers must use the same authentication key to establish a neighbor relationship. Using unique keys on each router will result in a mismatch.
- D. Incorrect.
Incorrect. OSPF router IDs do not need to be identical for neighbor relationships. In fact, they must be unique to avoid conflicts.