Restart the network from the command line in Ubuntu 16.04
#Restart Network on Ubuntu 16.04
sudo systemctl restart NetworkManager.service
sudo service network-manager restart
sudo nmcli networking off
sudo nmcli networking on
#Restart Network before Ubuntu 16.04
sudo /etc/init.d/networking restart
#or
sudo /etc/init.d/network-manager restart
#then
sudo ifdown -a
sudo ifup -a