On many laptop models with Ubuntu systems (Kubuntu, Lubuntu, Xubuntu etc.) the wireless network stops working after returning from sleep/standby mode. The problem is quite common and occurs in many versions of the system: 16.04, 14.04 and others. The article will describe a universal solution to this problem.
If your wifi “drops” when you exit suspend/hibernate/hybrid-sleep, don’t despair, just type in the command in the terminal:
sudo systemctl restart network-manager.service
If this command restarts wifi, then create the
/etc/systemd/system/wifi-resume.service file under the superuser:
sudo nano /etc/systemd/system/wifi-resume.service
With such content:
#sudo systemctl enable wifi-resume.service
Description=Restart networkmanager at resume
ExecStart=/bin/systemctl restart network-manager.service
Then activate this script:
sudo systemctl enable wifi-resume.service
And you can safely go into standby mode.
If rebooting the network-manager doesn’t help (which is rare in this case), look for a solution at the wifi-adapter driver level.