JNCIP-SP: Juniper Networks Certified Professional – Service Provider (2023) — Question 5

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

Answer options

• A. CSNPs are flooded periodically.
• B. PSNPs are flooded periodically.
• C. PSNPs contain only descriptions of LSPs.
• D. CSNPs contain only descriptions of LSPs.

Correct answer: A, C

Explanation

The correct answers are A and C. CSNPs (Complete Sequence Number PDU) are indeed flooded periodically to maintain the link state database, while PSNPs (Partial Sequence Number PDU) contain only summaries of LSPs, making option C correct. Options B and D are incorrect because PSNPs are not flooded periodically and CSNPs do not exclusively contain LSP descriptions.