OpenVPN configuration files + Ubuntu's network manager
Ubuntu Network Manager: Enabling and disabling An Alternative to Ubuntu network manager is systemd-networkd, which is the default backend service in Ubuntu server 18.04. So if you want to disable the NetworkManager, then the networkd service should be enabled, while it is better to disable networkd service when network manager is running. Disable Network Manager and enable systemd-networkd The existing answers for connecting VPN using L2TP VPN on Jul 25, 2020 Debian Network Manager Tutorial – Linux Hint NetworkManager seeks to keep connectivity through Ethernet, WIFI, PPPoE and allows VPN (Virtual Private Network). It has several graphical interfaces for GNOME, KDE, Cinnamon and more, it simplifies the network configuration including network devices, gateways configuration, IP address assignation, VPN, bridges, DNS and additional options. Network Manager download | SourceForge.net
OpenVPN Setup: Ubuntu 18.0 (via Network Manager) – StrongVPN
How to create a strongswan VPN connection in Ubuntu 16.04?
By default network management on Ubuntu Core is handled by systemd's networkd and netplan. However, when NetworkManager is installed, it will take control of all networking devices in the system by creating a netplan configuration file in which it sets itself as the default network renderer.
Best Free VPN for Ubuntu (14.04, 16.04 and 18.04) in 2020 May 05, 2020 How to create a strongswan VPN connection in Ubuntu 16.04?