Ubuntu / Linux Mint – Network Device Not Managed After PXE Boot

I utilize “Serva” to PXE boot just about every OS I could ever need in my small computer repair shop. It’s awfully handy to plug in an ethernet cable, and pick whatever operating system I need.

Linux Mint (or Ubuntu) began to have a nasty side-effect though when doing this. You see, they thought it was a good idea to move away from the ETH0 and ETH1 naming conventions, and instead use something completely different (I’ll edit this article once I’m back at a linux desktop that displays the new naming convention). This breaks manageability of the network, because after a PXE boot, the OS is expecting one name, and the network-manager tool is expecting something else.

Here’s how to fix the issue (and the source for this article is below; I’m putting this here on my own site, cause I’m scared poopless that it’ll 404 one day, and I’ll have no idea what the procedure was, since I just click my bookmark to address the issue when it arises).

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 you only have one NIC, you’re likely done at this point. If other devices appear 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

Source: Ubuntu – Network device not managed – [itso.dk]

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