6.3.5. Procedure – Reverting to an older firmware version


PSM can store up to five different firmware versions, any of them can be booted if required. The available firmwares are displayed on the Basic Settings > System > Firmwares page. The list shows the detailed version of each firmware, including the version number, the revision number, and the build date. The firmware running on PSM is marked with in the Current column. The firmware that will be run after the next PSM reboot is marked with in the After reboot column.

To boot an older firmware, complete the following steps:


When upgrading PSM, it is possible that the configuration file is updated as well. In such cases, simply rebooting with the old firmware will not result in a complete downgrade, because the old firmware may not be able to read the new configuration file. If this happens, access the console menu of PSM, and select the Revert Configuration option to restore the configuration file to its state before the firmware was upgraded. For details on using the console menu, see Section 6.5.1, Using the console menu of PSM.


Downgrading from the latest Feature Release, even to an LTS release, voids support for PSM.


  1. Navigate to Basic Settings > System > Firmwares.

  2. Select the firmware version to use, and click in the After reboot column.

  3. If you are downgrading a single PSM node:

    Select Traffic control > This node > Reboot to reboot PSM.

  4. If you are downgrading a PSM cluster:

    Follow the instructions described in Procedure 6.3.3, Upgrading a PSM cluster (skip the upload steps). Below is a summary of the necessary actions:

    1. You need IPMI (or direct physical) access to the slave node to proceed.

    2. Take the slave node offline.

    3. Restart the master node. Following reboot, verify that the master node was downgraded successfully.

    4. Use the IPMI interface to power on the slave node. Verify that the slave node reconnected to the master, and was downgraded successfully.