| Execute the command: execute restore image management-station ? It will bring up a list similar to below: 07002000FIMG0013702004 v7.02 MR2-GA-F P4 b1396 (upgrade)
07002000FIMG0013702002 v7.02 MR2-GA-F P2 b1255 (downgrade)
07000000FIMG0013700009 v7.00 GA-M P9 b0444 (downgrade)
07000000FIMG0013700008 v7.00 GA-F P8 b0418 (downgrade)
07000000FIMG0013700007 v7.00 GA-F P7 b0367 (downgrade)
06004000FIMG0013704012 v6.04 MR4-GA-M P12 b2060 (downgrade)
06004000FIMG0013704011 v6.04 MR4-GA-M P11 b2030 (downgrade)
06004000FIMG0013704010 v6.04 MR4-GA-M P10 b2000 (downgrade) The above is captured from the machine running on firmware v7.2.3 (v7.02 MR2-GA-F P3 b1262): - v7.02 -> Version 7.2.
- MR2-GA-F -> F for Feature Build and M for Mature Build.
- P4 -> Patch 4 (7.2.4).b1396 -> Build number.
For upgrading to v7.2.4, complete the command with its corresponding value as shown below: execute restore image management-station 07002000FIMG0013702004 Then, it will show the output: Getting image 07002000FIMG0013702004 from Management station...
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This operation will replace the current firmware version!
Do you want to continue? (y/n) Continue with prompts to complete the Upgrade or Downgrade process accordingly.
If the FortiGate is in an HA cluster, the secondary unit will upgrade first, followed by the primary. The following exhibits the output of the original Primary FortiGate when performing an upgrade in an HA cluster. FGT01 # Getting image 07004000FIMG0026804009 from Management station...
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This operation will replace the current firmware version!
Do you want to continue? (y/n)y Verifying the signature of the firmware image.
Warning: Installing image v7.4.9 from v7.4.8 may result in loss of configuration. Do you want to proceed?
Do you want to continue? (y/n)y Warning: Upgrading to an image with Mature maturity notation. Please wait for system to restart.
Wait for HA to be primary of all clusters...
Send image to HA secondary.
Wait for secondary to restart.......................................................................................
Wait for first secondary to become new primary.. ----> Firmware upgrade on secondary successful at this stage and rebooted successfully. The upgraded secondary will take over the primary role and allow the primary to upgrade. The following will be exhibited in the secondary FortiGate: FGT02 # Get image from ha primary OK.
Verifying the integrity of the firmware image...
Image verification OK! Check image OK. Please wait for system to restart. Firmware upgrade is in progress ... Done. The system is going down NOW! Important: - Take a backup of the Configuration File before performing the Upgrade/Downgrade, as, unlike the GUI, this process will not provide the option to take a backup nor automatically back up the configuration file during the upgrade process.
- It is impossible to recover the backup configuration file if it hasn't been downloaded before the upgrade is performed via this method.
- There should be proper connectivity to the FortiGuard Server to accomplish this process.
- The image to be upgraded must be available in FortiGuard Server to use this method.
- A certain delay will occur if multiple versions of FortiOS are being released within 2-3 days due to the uploading process. Run the command 'execute restore image management-station ?' after a day or two to check for the firmware availability.
- Manual upgrade via GUI is the next option if this method does not work. Refer to the article for the upgrade procedure: Technical Tip: How to manually perform a firmware upgrade from the GUI.
Disclaimer: Fortinet TAC does not provide standby support for firmware upgrades/downgrades. Call the Fortinet Support Hotline only when an issue is encountered during the upgrade/downgrade process. Furthermore, if an issue occurs as a result of a downgrade, be prepared to perform a TFTP format and reinstall operation to restore service: Technical Tip: Formatting and loading FortiGate firmware image using TFTP. | 
