Yes, there is a way to perform a hard reset on the NGAF device to restore it to its default settings, even if you cannot access the device through the network.
To do so, you will need to locate the reset button on the NGAF device. This button is typically located on the back of the device, and it may be labeled "reset" or "restore factory settings."
To perform the hard reset, follow these steps:
1-Make sure the NGAF device is powered on.
2-Locate the reset button on the back of the device.
3-Using a small object such as a paperclip or a pen, press and hold the reset button for at least 10 seconds.
4-Release the reset button after 10 seconds.
5-Wait for the NGAF device to reboot and initialize, which may take a few minutes.
6-Once the device has finished rebooting, it should be restored to its default settings, and you should be able to access the web admin interface using the default login credentials.
Note that performing a hard reset will erase all of your previous configurations and settings, so you will need to reconfigure the device from scratch after the reset.