I have a VPS (Cent OS 6) on a live IP. I have several other machines (All linux, mostly Cent OS 6 and a few Android devices) sitting behind NATted ADSL Routers on several sites.
I need to create a VPN between them, so that any device can ping or ssh into other devices participating in the VPN. Live Server can act as the host. Security is important.
I fairly comfortable with Linux CLI, but I don't know where to start for this project.
My questions is, What are the steps that I need to do to achieve the above setup?