If you have never upgraded the firmware of your professional Zyxel networking device, please stick to this tutorial to backup your configuration and upload the firmware image.
1. Visit the FTP site ftp.zyxel.com
2. Search for the subfolder of your device (e.g. ZyWALL USG 20W)
3. Enter the “firmware” folder and download the desired firmware datecode
4. Extract the downloaded zip-file
5. Access your device by entering its IP address in the browser address line and login by using the device’s credential
6. (Best Practice) Navigate to Maintenance > File Manager > Configuration File and copy the startup-config.conf and rename it
7. Enter the Maintenance > File Manager > Firmware Package menu
8. Browse to find the extracted firmware folder and select the .bin file contained in that folder
9. The firmware is being uploaded via webbrowser and afterwards applied. This may take several minutes. Please do not close the webbrowser or physically disconnect the unit.
10. To check if the device is finished with upgrading, you can ping the device constantly with ping “device’s IP” –t
11. If you are not able to reach the site or if you find that some configuration points seem corrupted/missing, please clear your browser cookies and cache, or use a private/incognito browsing window