[SOLVED] nmcli: Can't set device to "managed"

I have just installed Debian Buster on a workstation and have the time of my life configuring the network. The installation comes with NetworkManager by default. I want to run VMs on it and need a bridge that includes the NIC named eno1. For now, I would be happy to just connect eno1 to my network.

However, nmcli refuses to manage the interface.

$ nmcli device
DEVICE  TYPE       STATE      CONNECTION
eno1    ethernet   unmanaged  --
lo      loopback   unmanaged  --
$ sudo nmcli dev set eno1 managed yes
$ nmcli device
DEVICE  TYPE       STATE      CONNECTION
eno1    ethernet   unmanaged  --
lo      loopback   unmanaged  --

In /var/log/syslog, the following is printed:

NetworkManager[600]: <info> [1600257554.8363] audit: op="device-managed" arg="managed" pid=1662 uid=0 result="success"

Rebooting doesn't help.

Any suggestions where to look for more information and how to fix this?

Are you running a desktop? If so did you check the applet to see if it is enabled etc?

I'm running Buster in a VM but the network was automatically configured and didn't have to change anything.

Did you manually make any changes to some configuration file?

https://wiki.debian.org/NetworkManager

Originally Posted by michaelk Are you running a desktop? If so did you check the applet to see if it is enabled etc?

It's a desktop on a PC (not a VM), and the applet says "unmanaged".

Did you manually make any changes to some configuration file? https://wiki.debian.org/NetworkManager

Probably. I can't check this right now, but I will probably report a big facepalm in a few hours.

As promised, here is my facepalm. Indeed, eno1 was in an interfaces.d file. I should have known this. Thanks for directing me to the solution.

Just a SWAG...