JNCIS-ENT: Juniper Networks Certified Specialist – Enterprise Routing and Switching (2025) — Question 22

Which statement is correct about graceful Routing Engine switchover (GRES)?

Answer options

• A. The PFE restarts and the kernel and interface information is lost.
• B. GRES has a helper mode and are starting mode.
• C. When combined with NSR, routing is preserved and the new master RE does not restart rpd.
• D. With no other high availability features enabled, routing is preserved and the new master RE does not restart rpd.

Correct answer: C

Explanation

Option C is correct because GRES combined with NSR ensures that routing information is retained without restarting rpd on the new master Routing Engine. Options A and B are incorrect as they misrepresent the functionality of GRES, and option D is misleading because it suggests that routing preservation occurs without NSR, which is not accurate.