Openswan is an IPSec server that is configured on the Linux machine to provide the other end of the virtual network. I should mention one caveat up front: I've been unable to configure the VPN client ...
VPN (Virtual Private Network) is a technology that provides secure communication through an insecure and untrusted network (like the Internet). Usually, it achieves this by authentication, encryption, ...
You can create a free VPN service using software-based services like WireGuard. You can install it on your Mac or Windows device and connect other devices to it ...