JNCIP-SP: Juniper Networks Certified Professional – Service Provider (2023) — Question 38

Which two statements are correct about IS-IS interfaces? (Choose two.)

Answer options

• A. If a point-to-point interface is in both L1 and L2, separate hello messages are sent for each level.
• B. If a point-to-point interface is in both 11 and L2, one combined hello message is sent for both levels.
• C. If a broadcast interface is in both L1 and L2, separate hello messages are sent for each level.
• D. If a broadcast interface is in both L1 and L2, one combined hello message is sent for both levels.

Correct answer: B, C

Explanation

Option B is correct because a point-to-point interface in both L1 and L2 uses a single hello message for efficiency. Option C is also correct as broadcast interfaces send separate hello messages for each level to maintain clear communication. Options A and D are incorrect because they do not accurately describe the behavior of point-to-point and broadcast interfaces in IS-IS.