This is a quick post to document a problem that I have had with my atheros WiFi card on Ubuntu 11.04 (Natty Narwhal). I installed Natty on my servers as soon as it became available and the installation was a breeze. All my servers were up and running in no time.

I delayed the Natty upgrade a bit on my laptop because it contains way more custom repositories than my servers, and I did not know if anything was going to break after the upgrade. I finally took the plunge this afternoon and made the upgrade.

The first thing I noticed was that my Internet connection slowed to a crawl. Most of my requests timed out and I could not even browse my local network. A bit of Googling solved the problem: apparently, the new kernel and atheros driver did not play nice with hardware encryption.

So I modified the atheros config file to disable hardware encryption at module load time. Here is the script I used

sudo -s

echo "options ath9k nohwcrypt=1" > /etc/modprobe.d/ath9k.conf


That’s it. After the reboot, my WiFi connection worked perfectly. Hope this post helps anyone who is having similar problems.


  • dean, May 25, 2011 @ 8:29 pm Reply

    Thank you very much!
    I was going crazy over this. I’ve been having similar problems in 10.10 also, I found a workaround – constant pinging have kept the WiFi connection working. This “fix” stopped working in 11.04 :

  • Chris, May 26, 2011 @ 5:20 am Reply

    Thanks for putting up your easy to follow post. It works a treat.

  • kajendiran, June 11, 2011 @ 5:52 pm Reply

    your a ninja. Thank you.

  • Steven, July 3, 2011 @ 11:55 am Reply

    Cheers man!

    It worked for my HP Dv6 3032tx (Atheros driver ath9k)!

  • trinux, February 21, 2012 @ 12:43 pm Reply

    Thanks from Spain! 😀 It worked in my Trisquel 5.0 (Natty upstream)

    Regards, Vicente.

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