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Configuring Graceful Routing Engine Switchover in a Virtual Chassis

In a Virtual Chassis, one member switch is assigned the primary role and has the primary Routing Engine. Another member switch is assigned the backup role and has the backup Routing Engine. Graceful Routing Engine switchover (GRES) enables the primary and backup Routing Engines in a Virtual Chassis configuration to switch from the primary to backup without interruption to packet forwarding as a hitless failover solution. When you configure graceful Routing Engine switchover, the backup Routing Engine automatically synchronizes with the primary Routing Engine to preserve kernel state information and the forwarding state.

To set up the Virtual Chassis configuration to use graceful Routing Engine switchover (GRES):

  1. Set up a minimum of two switches in a Virtual Chassis configuration with primary-role priority of 255:
  2. Set up graceful Routing Engine switchover:

Commit the configuration.


We recommend that you use the commit synchronize command to save any configuration changes that you make to a multimember Virtual Chassis.