Nonstop Active Routing (NSR) for JN0-360 Exam

AD

In addition to maintaining interface and kernel information, NSR also saves routing protocol information by running the rpd process on the backup RE. By saving this additional information, NSR is self-contained and does not rely on helper routers to assist the routing platform in restoring routing protocol information. In addition to enabling NSR and GRES, you should also ensure that the commit operation synchronizes the configuration file by adding the commit synchronize statement under the [edit system] hierarchy.

Nonstop active routing (NSR) is a feature that allows a router's control plane to continue functioning without interruption during a Routing Engine (RE) switchover. This feature ensures that network traffic is not impacted during a planned or unplanned RE failover.

Here are the correct statements about NSR:

A. Graceful Routing Engine Switchover (GRES) must be configured for NSR to function properly

This statement is true. GRES must be enabled for NSR to function properly. GRES allows the new Routing Engine to take over smoothly without causing any disruption to the network. When GRES is enabled, the new RE will be ready to take over the primary RE's role and continue processing packets with minimal or no impact on network traffic.

B. NSR and graceful restart can be enabled at the same time

This statement is also true. NSR and graceful restart are two separate features that can be enabled together. Graceful restart enables a router to maintain its forwarding state during a restart or failover, while NSR allows the router's control plane to continue functioning without interruption.

C. NSR relies on helper support on neighboring devices

This statement is false. NSR does not rely on helper support on neighboring devices. However, the NSR feature does require that the neighboring devices support Nonstop Bridging (NSB) or Nonstop Bridging Extended (NSB-XT) features, which provide forwarding state preservation during the RE switchover.

D. When NSR is enabled, the rpd process runs on the backup Routing Engine

This statement is false. When NSR is enabled, the rpd process runs on both the primary and backup Routing Engines simultaneously. During a switchover, the backup RE takes over the control plane processing, and the rpd process continues running uninterrupted on the backup RE.

In summary, NSR is an important feature that provides network stability and continuity during Routing Engine switchover. It requires GRES to be enabled, can be used in conjunction with graceful restart, does not rely on helper support from neighboring devices, and runs the rpd process on both the primary and backup Routing Engines.