Troobleshooting Wifi on Linux

My system is a dual boot btw Debian and my network manager is NetworkManager.

Here is a listof command I ran to understand where were the issues (I suspected that My device was constinuously switching btw 5GHz and 2.4GHz bandwiths)

systemctl status NetworkManager
sudo nano /etc/NetworkManager/NetworkManager.conf

This showed me that my network interfaces weren’t properly managed by NetworkManager… Oops… So I set the value of [ifupdown] to true.

Of course one sudo systemctl restart NetworkManager.

paulb@debian:~$ nmcli device status
DEVICE        TYPE      STATE                   CONNECTION
wlo1          wifi      connected               mybox-****
lo            loopback  connected (externally)  lo
docker0       bridge    connected (externally)  docker0
p2p-dev-wlo1  wifi-p2p  disconnected            --

So it appeared that it wasn’t an issue about bandwiths but rather about IPv6…

I just set nmcli connection modify "mybox" ipv6.method "disabled" the connection and it worked very fine !

I just ran into this super website that helped me a lot to understand what was under the hood.

USEFUL TIPS

sudo journalctl -fu NetworkManager #interactive view of the journal
nmcli -f ALL device wifi show #shows wifi password and QRcode
nmcli connection down "mybox"
nmcli connection up "mybox" #cli connection

GOOD RESOURCE

• dedoimedo article about ipv6
• dedoimedo list of cool stuff