CCIE Service Provider (legacy) — Question 19

You are enabling NSF for IS-IS. What are two advantages of Cisco NSF variation over IEFT NSF? (Choose two.)

Answer options

• A. It does not rely on NSF-aware neighbors.
• B. It continues forwarding IP packets until route convergence is complete.
• C. It provides NSR in addition to NSF.
• D. NSF-capable router receives the adjacency and link-state information from NSF-aware neighbors.
• E. It allows the standby RP to take control of the device after a hardware or software fault on the active RP.

Correct answer: A, E

Explanation

Option A is correct because Cisco NSF can function without requiring NSF-aware neighbors, which enhances its flexibility. Option E is also correct as it allows for seamless failover to the standby RP during an active RP failure. Options B and C are incorrect because they either describe features not unique to Cisco NSF or do not highlight advantages over IETF NSF. Option D is wrong since it contradicts the independence from NSF-aware neighbors.