yikes! no internet

[Linux for blind general discussion]

Hello,
Suddenly my linux desktop has no inteqnet at all. I am doing this email with an ipad.
Wifi and the lan seem ok; the ipad has no problem connecting.
Where should I begin to find what is wrong?

Also i can no longer login to my router with the ipad.
I get this error message:
Error: ReferenceError: Can't find variable: isQCA
The router is an Arris model tg1672g.
The pc is a desktop running ubuntu.