I'm using Ubuntu 18.04.1 LTS. I want to disable network manager on an Ubuntu machine, because (1) I don't need it, (2) I prefer having hardcoded configuration, and (3) network manager regularly causes issues by changing the DHCP configuration.
I tried to follow the official documentation:
Stop network manager
sudo systemctl stop NetworkManager.service
Disable network manager (permanently) to avoid it restarting after a reboot
sudo systemctl disable NetworkManager.service
Despite this, the network manager is back again every time I reboot the machine.
How can I make it go away?