Why is my wifi down? An occasional problem
December 12, 2019
Hey Heather. It’s me again.
I accidentally turned off my computer when moving it around and this broke wifi. I brought this upon myself really. A few days ago I did a system update and didn’t reboot. Honestly, I just have a heedless heuristic when it comes to rebooting which goes something like this: reboot when kernel is updated or whenever I accidentally closed all tabs in the browser. I could do better. Anyway! I find this to be the most annoying problem on a laptop because you’re relegated to using your phone for search. This isn’t the first time I’ve had issues with wifi. It had been a while though so I didn’t remember what I had done. This will serve as a reminder for when it will inevitably happen again. FYI: the distro I use is Arch Linux.
Because it’s the most frequent case that has happened to me, it’s the first one
I should check whenever wifi isn’t working. On my laptop, the F8 key toggles the
wireless card. That key is right above the number 7 so I’ve inadvertently
pressed it without noticing. I’ve also seen laptops with an inconspicuous switch
that will also turn off the wireless card. The fact that these slips are quite
subtle makes it harder to figure out what you did and just emphasizes the I
don’t even know what happened! If you want to check if you’ve toggled the
wireless card you can use
rfkill. You can read the documentation on the arch
$ rfkill list --------------------- 2: phy0: Wireless LAN Soft blocked: no Hard blocked: no
If Hard blocked is set to yes, you’ll need to toggle the hardware switch. If
Soft blocked is set to yes then you can use the command
# rfkill unblock
What happened this time
I’m not sure anymore, I was supposed to write this two weeks ago. But I do know my initial reaction to wifi not working was But I didn’t even do anything! Once I got over that I started trying to debug the problem. I remember it was pretty straightforward to figure out what the issue was but not how to resolve it. It’s a little difficult to remember what I did exactly because now that everything is working I’m getting no error messages. Anyway I’ll go from memory and write the commands I believe I used.
First command I ran was probably
netctl stop home, followed by
home. I believe this would have brought up a message saying that it didn’t work
and that I should check
journalctl -xe and
email@example.com. An error message said something along the lines of
firmware missing. I ran two other commands
ip addr and
lspci -v. The
first command didn’t show my network device but it existed when I ran the second
command. Here’s what the output of these commands may look like if working
$ ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever 2: enp0s31f6: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 70:5a:b6:8a:a0:87 brd ff:ff:ff:ff:ff:ff 3: wlp58s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 70:5a:b6:8a:a0:87 brd ff:ff:ff:ff:ff:ff $ lspci -v (... this output has been shortened ... ) 3a:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78) Subsystem: Intel Corporation Dual Band Wireless-AC 8265 Flags: bus master, fast devsel, latency 0, IRQ 126 Memory at ec000000 (64-bit, non-prefetchable) [size=8K] Capabilities: <access denied> Kernel driver in use: iwlwifi Kernel modules: iwlwifi
At this point I knew that I needed a firmware update. Eventually I would have to
$ sudo pacman -Syu linux-firmware (unsure where I found out I needed
linux-firmware specifically) but to do this I need to be connected to the
internet. Thankfully I found an ethernet cable at home. So now I just needed to
figure out how to connect to the ethernet. Apparently many distros have it set
up so that you can connect the cable and it just works. This was not my case.
After a lot of searching around I found that I had to run something like
link set enp0s31f6 up. I may have used
modprobe too but I’m not sure if it
was useful at all.
Here are some of the resources I consulted in the Arch Wiki: network configuration, /ethernet, /wireless. I had also consulted a few answers on Stackoverflow and on the Arch forum under the Newbie corner but unfortunately I don’t remember which ones were helpful. I think these notes are enough to kind of guide me (and maybe others) whenever this happens again.
Anyway this is as much as I remember. Another thing that was important was to take a break. I got pretty upset when this happened because I was in the middle of something. I hadn’t eaten so that wasn’t helping. I just want to finish this ONE thing I had said to myself and then this happens. I took some time to get a cup of coffee and some food which really helped me change my mindset from thinking of one problem and switching to another.