How can I check if a device is managed through NetworkManager?

How can I distinquish if a device (ethernet in this case) is managed by the NetworkManager?

At first I execute,

$ nmcli device
DEVICE TYPE STATE CONNECTION
enp0s3 ethernet connected Wired connection 1
lo loopback unmanaged -- 

where I see that the ethernet is connected but it doesn't tell me if the device is managed or not. The default is false inside /etc/NetworkManager/NetworkManager.conf so I changed it to true and restart the service,

$ sudo systemctl restart NetworkManager
$ nmcli device
DEVICE TYPE STATE CONNECTION
enp0s3 ethernet connected Wired connection 1
lo loopback unmanaged -- 

but again I don't see specific info that ethernet is managed or not.

1 Answer

grep -i renderer /etc/netplan/*.yaml will tell you if NetworkManager has been chosen. Also, your ethernet would show up as disabled or unmanaged if somebody wasn't managing it.

Create this file...

sudo -H gedit /etc/network/interfaces

add the following...

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

Reboot, or restart NetworkManager. Then nmcli device should show lo as managed. lo is the loopback device.