System status Changing the FortiGate firmware
FortiGate-4000 Installation and Configuration Guide 105
If you are reverting to a previous FortiOS version (for example, reverting from FortiOS
v2.50 to FortiOS v2.36) you might not be able to restore the previous configuration
from the backup configuration file.
To revert to a previous firmware version using the web-based manager
1 Copy the firmware image file to your management computer.
2 Log into the FortiGate web-based manager as the admin administrative user.
3 Go to System > Status.
4 Select Firmware Upgrade .
5 Type the path and filename of the previous firmware image file, or select Browse and
locate the file.
6 Select OK.
The FortiGate unit uploads the firmware image file, reverts to the old firmware version,
resets the configuration, restarts, and displays the FortiGate login. This process takes
a few minutes.
7 Log into the web-based manager.
For information about logging into the web-based manager when the FortiGate unit is
set to factory defaults, see “Connecting to the web-based manager” on page 44.
8 Go to System > Status and check the Firmware Version to confirm that the firmware
is successfully installed.
9 Restore your configuration.
For information about restoring your configuration, see “Restoring system settings” on
page 116.
10 Update antivirus and attack definitions. For information about antivirus and attack
definitions, see “Manually initiating antivirus and attack definitions updates” on
page 125.
Reverting to a previous firmware version using the CLI
This procedure reverts your FortiGate unit to its factory default configuration and
deletes NIDS user-defined signatures, web content lists, email filtering lists, and
changes to replacement messages.
Before beginning this procedure you can:
• Back up the FortiGate unit configuration using the command execute backup
config.
• Back up the NIDS user defined signatures using the command execute backup
nidsuserdefsig
• Back up web content and email filtering lists. For information, see the FortiGate
Content Protection Guide.
Note: Installing firmware replaces the current antivirus and attack definitions with the definitions
included with the firmware release that you are installing. After you install new firmware, use the
procedure “Manually initiating antivirus and attack definitions updates” on page 125 to make
sure that antivirus and attack definitions are up to date.