Recently we were working on a
Fedora 27 GNU/Linux box where we needed to completely disable the Network Manager.
Initially, we just stopped the
NetworkManager service and then disabled it thinking that it would be enough.
To our surprise after we rebooted the box, we noticed that the Network Manager was active again!
After some research we found out that another service called
NetworkManager-wait-online was starting the
NetworkManager as some sort of recovery mechanism.
So, in order to permanently block
NetworkManager from starting on boot, we disabled
NetworkManager-wait-online as well.
In the end our solution to disable the
NetworkManager service came down to executing the following commands as root (or using
systemctl stop NetworkManager; systemctl stop NetworkManager-wait-online; systemctl disable NetworkManager; systemctl disable NetworkManager-wait-online;