Comment # 20 on bug 893678 from Marius Tomaschewski

A "systemctl stop NetworkManager" is not sufficient -- there is a NM setting
causing to stop NM only, but not the dhclient processes started by NM...

See also bug#895447 => "systemctl --kill-who=all kill NetworkManager".

We're working on a documentation how to do it manually -- here the a paste
from current draft:

"[...]
Procedure to enable NetworkManager manually:

1) First, stop the running network (wicked) service to get a clean state
(configuration may differ):

systemctl     is-active network.service && \
systemctl     stop      network.service

2) Then, stop the wicked-daemon services as well:

systemctl     is-active wickedd.service && \ 
systemctl     stop      wickedd.service

3) Disable wicked, enable NetworkManager.service (creates alias link):

systemctl disable wicked.service 
systemctl --force enable NetworkManager.service

4) Start the NetworkManager service via the alias link:

systemctl     start     network.service

or directly:

systemctl start NetworkManager.service


Procedure to disable NetworkManager and switch to wicked.service manually:

1) Stop the running NetworkManager.service:

systemctl     is-active NetworkManager.service && \ 
systemctl --kill-who=all kill NetworkManager.service

Note: The normal NetworkManager.service stop action stops NetworkManager, but
leaves processes such as dhcp clients running to not break network connectivity
when it is restarted on update or there is a remote fs mounted while shutdown.
The --kill-who=all kill action ensures to stop them too as they conflict with
the wicked service using a different implementation.

2) Disable NetworkManager, enable wicked.service (creates alias link):

systemctl disable NetworkManager.service 
systemctl --force enable wicked.service

3) Start the new network.service, which now is wicked.service:

systemctl start wicked.service

or via the alias link:

systemctl start network.service

The wickedd daemon service are started automatically via dependencies.[...]"