OpenVPN Client on Ubuntu 16.04
Assuming you already have an OpenVPN server running, installing the OpenVPN client on Ubuntu is pretty easy. We need the openvpn package as well as the plugin for the network manager.
apt-get install network-manager-openvpn-gnome network-manager-openvpn openvpn
Next, open the Network application.
Click on the plus sign in the bottom left of the Network window.
We want a new VPN connection, so choose VPN and click Create.
The next step assumes you already have an exported archive configuration from your OpenVPN server, including the .ovpn file, the server certificate, and server key. Import the .ovpn config file and enter any user credentials that may be required. Save the configuration.
Finally, load the new VPN connection from the network icon as shown below to start the VPN. A small lock icon will appear on the network icon indicating the VPN is active.