How to let NetworkManager manage WLAN interface after upgrade?

Question

I upgraded a Ubuntu system from 11.04 to 11.10 via do-release-uprade.

Now some things does not work as before.

For example now, my user needs to be part of the scanner group to be able to use xsane etc. - with < 11.10 this apparently was not necessary.

To be able to use nm-applet again (for wired networking) I needed to add the user to the group netdev after the upgrade.

But WLAN management still does not work via NetworkManager - nm-applet just does not display any wireless devices.

In the logs there is:

NetworkManager wlan0 deactivating device reason managed

(inter-punctuation removed)

But why it is suddenly managed?

I checked /etc/network/interfaces and it does not contain any wlan0 entries.

And /etc/NetworkManager/NetworkManager.conf just contains:

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=true

Is there some other group the user needs to be part of? Or what else could be messed up after an upgrade?

Manually connecting to a WLAN-AP via wpasupplicant and dhclient (after stopping NetworkManager) works perfectly fine.

Edit: Btw, this Ubuntu system is a little bit non-standard:

• wdm is configured as display manger instead of lightdm
• as window manager I use awesomewm

Solution

Please backup before you use the commands below, I don't know if you will have internet afterwards.

Connect using ethernet cable.

1. Download the packages so you have a way to reinstall them even without internet:

   cd
   apt-get download network-manager-gnome network-manager
   

2. Then I'd suggest to purge your network manager configuration:

   sudo apt-get purge network-manager-gnome network-manager
   sudo rm -rf /etc/NetworkManager
   sudo rm -rf /usr/lib/NetworkManager
   sudo rm -rf /var/lib/NetworkManager
   

3. And reinstall network manager:

   sudo apt-get install network-manager-gnome network-manager
   

   If you don't have internet anymore try installing the local packages we downloaded with the first command:

   cd
   sudo dpkg -i network-manager*.deb
   

4. Restart the computer.

If the above commands did not fix the internet, we need more info:

1. Run these commands and provide the output (edit your question):

   sudo apt-get dist-upgrade
   cat /etc/network/interfaces
   iwconfig
   ifconfig
   lspci -nn
   lsusb
   nm-tool
   sudo lshw -C network
   rfkill list all
   

2. Check that you have all the dependencies installed correctly, reinstall the ubuntu meta-packages:

   sudo dpkg -P --force-all ubuntu-desktop ubuntu-standard ubuntu-minimal
   sudo apt-get install ubuntu-desktop ubuntu-standard ubuntu-minimal
   

3. You never mentioned which Ubuntu version you used before you upgraded to 11.10.

Note: By the way, AFAIK the do-release-uprade command should be used when upgrading server installations, not desktop. You should prefer downloading the alternate cd of the through update-manager.

Comments

[maxschlepzig]

Nice write up - I will try it after a proper backup - I upgraded from the previous version (i.e. Natty, which is 11.04)

[maxschlepzig]

Ok, removing those NM directories and reinstalling did not help, looked at the output of nm-applet and there seems to be a dbus permission problem: _nm_object_get_property: Error getting 'ActiveConnections' for /org/freedesktop/NetworkManager: (9) Rejected send message - I'll post a new question for this

[maxschlepzig]

See also my other answer.