Before performing manual Graceful Routing Engine Switchover (GRES) with Non-Stop Routing (NSR), it is recommended that several checks should be run to ensure that the primary and backup Routing Engines are in sync. This article provides the list of commands that can be used to run the required check, and explains the check that a particular command is running.
show system switchover
-
This command should be executed only on the backup Routing Engine. The command is not supported on the master RE because the kernel-replication process daemon does not run on the master RE.
-
The command gives the overall health of GRES, whether it is configured or not, whether the management process (MGD) has synchronized configuration from the master to the backup, 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 master to the backup 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.