Ubuntu – Network device not managed

While putting Ubuntu 16.04 on my PXE install/nfs  server, I found that after an install, I was unable to my onboard NIC working through Network-Manager.

After digging a little around the net, I found this thread: askubuntu tread

To fix the problem, you need to edit /etc/NetworkManager/NetworkManager.conf, and replace “managed=false” with “managed=true”

Instead of using a normal editor, I want to use “sed” command:

sudo sed -i.bak s/false/true/g /etc/NetworkManager/NetworkManager.conf
sudo systemctl restart NetworkManager

If other devices appears in Network manager, they may be set in /etc/network/interfaces

Delete all content of /etc/network/interfaces

and insert:

auto lo
iface lo inet loopback




Now you should see you NIC in NetworkManager


  • Michael Miller

    Thank you. This has saved my bacon. We extensively deploy Linux Mint 18.3 MATE (and other flavors of Linux) via Vercot’s Serva application, which allows us to deploy via PXE. Every time it booted up for the first time, my Ethernet would mention it was unmanaged, and have zero connectivity.

    I used a USB to ethernet adapter, googled “Unmanaged Network “PXE” linux boot” and found this.

    There are zillions of people that recommend doing this and that online for this issue – but not many have the solution. This one is THE ONE. Thank you!