Applying a configuration file to a Fortinet Fortigate Firewall

• General assumption: The device is configured according to factory defaults.
• Connect to the serial console of the device (just like to a Cisco device, same serial port settings)
• Log in using username admin and no password (just hit ENTER).
• Connect your computer's network port to the MGMT network port of the device. Configure your computer's NIC to use a static IP address in the 192.168.1.0/24 subnet (e.g. 192.168.1.100/255.255.255.0).
• Access the device's web interface on https://192.168.1.99 and log in with the same credentials as above.
• In the navigation bar go to System → Config → Advanced

• In the Scripts section of the page, select Upload Bulk CLI Command File and select your config file.
• Hit Apply. You'll lose connection almost instantly, as most probably the config filewill set the IP address of the MGMT interface so something other than 192.168.1.99.
• In the CLI window (serial terminal), check if the hostname has changed and now matches the hostname in your config file. Optionally, check the complete config by issueing the show full-configuration command.
• The new config is now applied and saved to the device.