Ubuntu 20 seems to manage networking devices differently. All instructions on disabling wlan0 are tailored to Ubuntu 19 and earlier. I tried blacklisting 'wlan0' in modprobe.d, didn't work.
24 Answers
Following the same principle and dogma (everything changes, "panta rhei") as in the previous comment, please do the following on a raspberry pi 4, having Ubuntu 20.04 LTS.
Add these two lines in the file /boot/firmware/usercfg.txt and never edit the "config.txt".
dtoverlay=disable-wifi
dtoverlay=disable-bt Figured it out! Edit /boot/firmware/usercfg.txt. add in
dtoverlay=disable-wifi.save and reboot
I don't know if anyone is looking for this, I haven't found an answer anywhere so hopefully it will help someone else.
For Ubuntu Core 20, the config.txt is found at /run/mnt/ubuntu-seed/config.txt. Add your config there. The active file is found at /var/lib/snapd/seed/config.txt, which is a read-only copy of the latter overwritten at boot.
Everything changes, "panta rhei" an so on, and so on... Nowadays, using Raspberry Pi 3B and Ubuntu Server 20.10, the proper file is: /boot/firmware/config.txt. I added there:
dtoverlay=disable-wifi
dtoverlay=disable-bt Because, BT is also unwanted for my servers' purposes. Reboot and wifi disappeared. Hope BT too.
Beware: file: /boot/firmware/config.txt isn't empty, so editing it try to not have zeroed its content.
Thanks for leading toward the right way.
Greetings.
