Help! My internet disappeared!

I don’t mean it stopped working, i really mean it disappeared: when i powered on the computer no internet devices showed in the network menu, and the only device was the loopback device. I have no idea why this happened! I assume that it must have been me that did something wrong because usually these things simply don’t happen on debian.

No matter. First, let’s make use of the journal to see why there’s no wifi device showing up:

sudo journalctl -f | grep iwlwifi
        

My wifi device is called iwlwifi, which is why i’m searching for that. The journal updates as more gets added to it, so i can just leave this open and watch what happens. Next, because i know that the wifi used to work on here, i’m going to open a new terminal and see what happens when i add the iwlwifi module to the kernel:

sudo /usr/sbin/modprobe -r iwlwifi && sudo modprobe iwlwifi
        

This caused me a problem, it said “no suitable firmware found!”, said which version was required, and had a link to the linux-firmware git repository. I opened it on my phone (because i couldn’t open it on the computer), downloaded the plain file, copied it to my computer over usb, and then copied it into the /lib/firmware directory. Finally, we can run the same command as above to load this new version.

That was a little scary, and i still don’t know why it happened. But at least it works now!