Description

Before you manually perform Graceful Routing Engine Switchover (GRES) with Non-Stop Routing (NSR), we recommend that you run a few checks to ensure that the primary and backup Routing Engines are in sync. In this article you will find the list of commands that you can use to run the required check, and also an explanation of the check that a particular command is running.

Solution

show system switchover

  • You should execute this command only on the backup Routing Engine. The command is not supported on the primary RE because the kernel-replication process daemon does not run on the primary RE. 

  • The command provides information about the overall health of GRES, whether it is configured or not, whether the management process (MGD) has synchronized configuration from the primary RE to the backup RE, whether the kernel has replicated any states in the last 5 seconds, and if the Packet Forwarding Engines (PFEs) are ready for GRES. 

Note: It is possible that the output shows the kernel state as “synchronizing.” This is perfectly fine even after the system is GRES ready. It just means that some states got replicated from the primary RE to the backup RE in the last 5 seconds. It may not be related to GRES readiness.

request chassis routing-engine master switch check

  • This command checks the GRES readiness state for the kernel synchronization process (ksyncd), the kernel, and the chassis process (chassisd).

  • For more information, see request chassis routing-engine master.

show task replication

  • This command checks for Routing Protocol Process (rpd) related replication.

  • For more information, see show task replication.

show database-replication summary

Note: This command is not needed when no subscriber management runs on the particular route.

Modification History

2021-03-25: Updated the article terminology to align with Juniper's Inclusion & Diversity initiatives.

2022-10-19: Article checked for accuracy and found to be valid and useful