OpenVPN is a full-featured, open-source Secure Socket Layer (SSL) VPN solution that accommodates a wide range of configurations. In this tutorial, you will set up an OpenVPN server on an Ubuntu 18.04 server and then configure access to it from Windows, macOS, iOS and/or Android. This tutorial will keep the installation and configuration steps as simple as possible for each of these setups.

Source: How To Set Up an OpenVPN Server on Ubuntu 18.04 | DigitalOcean