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Configuring Nonstop Active Routing on Switches

Nonstop active routing (NSR) provides a mechanism for transparent switchover of the Routing Engines without necessitating restart of supported routing protocols. Both Routing Engines are fully active in processing protocol sessions, and so each can take over for the other. The switchover is transparent to neighbors.

You can configure NSR on an on a Juniper Networks EX Series switch with multiple Routing Engines or an EX Series or QFX Series switch in a Virtual Chassis or Virtual Chassis Fabric configuration.

To configure nonstop active routing:

  1. Enable graceful Routing Engine switchover (GRES):
  2. Enable nonstop active routing (by default, nonstop active routing is disabled):
  3. Synchronize configuration changes between the Routing Engines:

    If you try to commit the nonstop active routing configuration without including the commit synchronize statement, the commit fails.


There is no requirement to start the two Routing Engines simultaneously. If the backup Routing Engine is not up when you issue the commit synchronize command , the candidate configuration is committed in the primary Routing Engine. When the backup Routing Engine is inserted or comes online, its configuration is automatically synchronized with that of the primary.

Best Practice:

After a graceful Routing Engine switchover, we recommend that you issue the clear interface statistics (interface-name | all) command to reset the cumulative values for local statistics on the new primary Routing Engine.

To disable nonstop active routing: