I am a newbie to openWRT and I started with flashing the Image into C7 and ssh/connecting to it via LAN port. Everything went well until I accidentally changed the SSH access interface to WAN in LUcI, and after that I cannot ssh nor connect to LUcI web. The C7 WAN port was connected to my home router's LAN interface, but I failed to ssh to C7's DHCP IP. Then, I directly connected my PC to the WAN port, but I still cannot ssh to into C7. Does anyone know how I could do?
Because I am not able to connect to the device, I tried to use the reset button of C7 to return to factory default setting, but it seems that the reset button isn't working. Is there any way that I can return to C7 factory default or flash the openWRT image into it without ssh/connecting to webUI?
If you changed only the ssh access interface, then luci is not affected. Try to clean browser cache, try private/incognito mode, try another browser.
WAN port by default doesn't allow any incoming connections, so you cannot login from ssh or luci.
If all that fails, go for the tftp restore that @faser suggested.