Roll Back the Software to a Previous Version | Junos OS Evolved | Juniper Networks

SUMMARY Junos OS Evolved maintains multiple versions of the software and configuration files on
the primary solid-state drive (SSD) on the Routing Engine. Each time you issue the
request system software add operational mode command, the previous software
image and configuration is preserved automatically. The last running software image and
corresponding configuration file is the default rollback image. Older images, along with the
configuration present when the older image was running, are preserved as well.

You use the rollback image and configuration preserved by default to revert to a prior
image on the same disk as the current image.

After an upgrade or a roll back, if the software is unable to use the current
configuration, the Routing Engine is often still reachable using the current management
interface configuration. If the management interface does not come up, use the console to
connect to the device to roll back the software and configuration.

After an upgrade, if the installation fails during early boot, the Routing Engine
automatically reverts to booting from the secondary SSD, where snapshots are stored. You can
then reboot the Routing Engine using the snapshot saved on the secondary SSD. You can then
roll back the software version, especially if the snapshot version is not a recent-enough
version of the software and configuration.

For a dual-Routing Engine device, the request system software rollback
operational mode command reverts both Routing Engines to the rollback software version. For
all devices, the command rolls back the software version on the FPCs as well.