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After having upgraded my Ubuntu from 12.10 to 13.04 the wireless device has stopped working. It simply does not show up in the panel nor in the network settings.

lspci gives:

$ lspci -nn -d 14e4:
02:00.0 Network controller [0280]: Broadcom Corporation BCM4321 802.11a/b/g/n [14e4:4328] (rev 03)

I have enabled the Broadcom driver under addtional drivers. Also I have run

$ sudo apt-get install firmware-b43-installer b43-fwcutter 

without error messages... However, when I run

$ sudo modprobe b43

my wifi shows up.

Now, my questions are:

  • What does modprobe do?
  • How to enable modprobe on startup automatically?
  • Is this legit or a workaround that may lead to more trouble in future?
share|improve this question
Before we propose the wrong solution, let's verify the correct driver for your wireless card. Please open a terminal and run: lspci -nn -d 14e4: Edit your question with the result and we'll proceed. – chili555 May 6 '13 at 12:41
Thanks in advance. I will do so in about 3 hours ... – Jan May 6 '13 at 12:46
Sorry, I didn't get back to my laptop yesterday. Now, I have edited the question. – Jan May 7 '13 at 12:55
up vote 1 down vote accepted

If b43 is working well, let's make it persistent. Please open a terminal and do:

sudo apt-get remove --purge bcmwl-kernel-source

It may not be installed; that's fine, just proceed:

sudo su
echo b43 >> /etc/modules

Now does it work as expected on reboot?

share|improve this answer
It does! Thanks a lot. I am not so good in Ubuntu, but whenever you have questions on scientific computing I will be happy to help with that. – Jan May 7 '13 at 21:41

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