Stop Ubuntu 11.10 killing your network!

Posted on March 26, 2012


Important update

To be fair to Canonical, I have found that openSUSE 12.1 also suffers with this bug and the same fix works. I want to keep opinion out of this blog but I can’t help but wonder why these major distributions do not care that their product can destroy a wireless network in seconds.

Target audience

Anyone who’s router is being killed by Ubuntu 11.10 when using an Intel wireless ‘N’ card.

About this tutorial

I have found many posts on the Internet about this but none of the solutions proposed worked. OK, that’s not exactly true; turning off ‘N’ on the router stops it from collapsing but that penalises any one else using the network. Some how that sits wrong with me. This is what fixed the issue for me so fire up the terminal and prepare for some command line magic.

1. Become root. You will need the full root environment as running step 2 prefixed with sudo will not have the required permission.

sudo -i

2. Set the options for the driver to disable ‘N’. The following command creates a file called iwlagn.conf in the /etc/modeprobe.d directory which will be read when the driver is loaded. When Canonical pull their finger out and release a patch for this nasty bug or release Precise Pangolin which reportedly fixes the bug you can simply remove this file and disable / enable your driver again.

echo “options iwlagn 11n_disable=1” > /etc/modprobe.d/iwlagn.conf

3. Disable your Intel wireless driver

modprobe -rf iwlagn

4. Re-enable your Intel wireless driver

modprobe -v iwlagn

Posted in: Hints and Tips, Linux