Ubuntu – Ethernet Network card BCM4401-B0 no longer recognised

broadcomethernetnetworking

I updated Ubuntu to 14.04 LTS and I can no longer see my network – No network devices available shows in the network drop down menu. Networking is enabled and if I choose to boot my Dell Inspiron 1300 from the network I do see some activity on the card but none in Linux. Both lights on the nic stay on permanently.

I don't know where to look for the equivalent of event viewer or similar to even start to troubleshoot, having only about two hours with the install before I updated. Original install was last October.

Any pointers on where to look in logs etc would be gratefully received.

02:00.0 Ethernet controller [0200]: Broadcomm Corporation BCM4401-B0 100base-tx [14e4:170c] (Rev 02)
Subsystem dell Device [1028:01c9]

cat /etc/modprobe.d/blacklist-bcm43.conf
# Warning: This file is autogenerated by bcmwl. All changes to this file will be lost. 
blacklist b43 
blacklist b43legacy 
blacklist ssb 
blacklist bcm43xx 
blacklist brcm80211 
blacklist brcmfmac 
blacklist brcmsmac 
blacklist bcma 
blacklist b44 
install wl 
modprobe -r b43 b44 b43legacy ssb; modprobe --ignore-install wl ; modprobe --ignore-install b44

Best Answer

Your wired network driver b44 is probably blacklisted by your wireless driver.

This should be fixed by

sudo -H gedit /etc/modprobe.d/blacklist-bcm43.conf

And removing blacklist b44, b44 and ; modprobe --ignore-install b44 from the last line.

The file should look this way

# Warning: This file is autogenerated by bcmwl. All changes to this file will be lost. 
blacklist b43 
blacklist b43legacy 
blacklist ssb 
blacklist bcm43xx 
blacklist brcm80211 
blacklist brcmfmac 
blacklist brcmsmac 
blacklist bcma 
install wl 
modprobe -r b43 b43legacy ssb; modprobe --ignore-install wl

Save the file.

After that wired network should work after reboot.

Note In case bcmwl-kernel-source is upgraded, this procedure probably should be done again.