Wednesday, April 18, 2012

No network connection, a weird problem...

This post is related to a problem that some users of Ubuntu came across to a bug that prevents their system to establish connection when using the latest version of Optimus Kernel and describes a permanent solution to it.

Many users contacted us reporting a weird "Network Connection" problem when they installed the latest Optimus Kernel. Wile we were testing to see if this is just a "Optimus Kernel" issue, we saw that in the latest version of Ubuntu 12.04 Beta this is not an issue. We are not 100% certain what had cause this but we have found the one to blame: AppArmor

It seems that the version of AppArmor that is present in Ubuntu 11.10, doesn't let DHCP to establish a network connection. So in the meantime we have a permanet workaround. This will put DHCP daemon in a complain mode so that it will not be enforced by AppArmor to not make connection and so DHCP will just be let alone.

Here is what you can do only once:

First install apparmor utilities from Software Center or from terminal:
sudo apt-get install apparmor-utils
Then in your terminal login as a root! (this is necessary as plain "sudo" will not work)
sudo -i
Then you need to add DHCP in complain mode:
aa-complain /sbin/dhclient
Now that you have added DHCP in complaint mode if you check it, it should be listed in complaint mode apps: 

Now you should be able to establish network connection.

Hope we have resolved the issue for all optimus kernel users and we would be glad to hear back from you if you have any other problems.


  1. It was very nice article and it is very useful to Linux learners.We also provide Linux online training

  2. Well It Was Very Nice Article It Is Very Useful For Linux Learners. We Are Also Providing Linux Online Courses Training. Our Linux Online Training Is One Of The Best Online Training Institute In The World.