Fix Broadcom slow wifi with Debian 11 bullseye
This is what worked for me:
- Open a terminal (alt+F2, Ctrl+alt+F2)
- log in as administrator
- type in
nano /etc/apt/sources.list
- add the line
deb http://deb.debian.org/debian bullseye contrib non-free
- save and exit
Strg+X y [Enter button]
- type in
apt-get update
apt-get install linux-image-$(uname -r|sed 's,[^-]*-[^-]*-,,') linux-headers-$(uname -r|sed 's,[^-]*-[^-]*-,,') broadcom-sta-dkms
- press the enter keyboard button
- Turn computer off and on again (reboot).
Source: the the debian wiki
Download speed before was 500kb/s and upload 5mb/s, even on a local network. After that Download is at least 60mb/s and upload at least 20mb/s.