For example, I will update ASUS RT-N12_VP with firmware 18.104.22.168.374.880 to 22.214.171.124.376.3835.
I will describe the actions:
1) Download the new firmware from the official site
2) Open the router settings by typing the address http://192.168.1.1 in the browser (maybe 192.168.0.1) and enter the standard login – admin, the password – admin
3) In the interface that opens at the bottom left, open the Administration menu, select the Firmware Update tab, click Browse in the window that opens and select the firmware that you previously downloaded and unpacked from the archive, and click Submit to start the update process. I have the specified message:
Firmware is upgrading. Please wait about 3 minutes
At the end a message was displayed that the router must be rebooted manually. To do this, click on the “Reboot” button at the top or simply turn it off and turn it on.
On the test, the settings remained unchanged.
I updated the firmware of the ASUS RT-N12VP router remotely.