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!

    • proud Daddy

      hey @Michael Miller . sorry for hijacking this thread, but the one i wanted to speak to you on apparently is closed and there is no way to contact you directly (are we de-evolving?). 🙁
      im wondering if you have found a non-cloud solution yet for your NAS backup, to replace crashplan? i just built my first server got super excited about setting up another couple at some other friends small businesses, but apparently they went the way of the buffalo! no idea how to PM through this weird website, so i hope this gets to you; and i can tell you replied!

      • Michael Miller

        Finally noticed this. And YES, I found a solution. It’s not as easy as install-app-on-both-ends like Crashplan, but, not terrible either if you enjoy a good tinker.

        Duplicati. Start reading up on it, and install it on the server that you want to back up FROM. They have a LOT of pathways in their web-UI (available after a quick install) that allow backing up to external devices directly plugged in, all the way to SFTP to a different location over the internet (this is what I did).

        I think the trickiest part was finding a good for-dummies article on setting up a Server 2016 box as an SFTP endpoint. After I got that set up, and had credentials and port forwarding set up correctly, I tested the connection with filezilla. After I had success, I plopped the credentials into the Duplicati web-UI, selected my giant 5TB of crap I needed to back up, and let’r rip.

        So far so good! It’s a shame there isn’t a “Duplicati on this end and that end, do the hard part for me” mode – but se la vi I guess.

    • Hi Michael,

      You are very welcome. I have not tried Vercot’s Serva application, but I have set up a simple pxe boot environment on small low power machine. Works great.