nmcli is a command-line tool for controlling NetworkManager and getting its status. It is not
meant as a replacement of nm-applet or other similar clients. Rather it's a complementary util‐
ity to these programs. The main nmcli's usage is on servers, headless machines or just for
power users who prefer the command line.
nmcli con down id 'Connection'
nmcli con up id 'Connection'