I'm working on a software appliance based on linux platform. I want to have a secured way of reaching every installed appliance over the Internet for remote debugging and support. In order to traverse NAT and to be able to simply connect to the appliance I was thinking about OpenVPN as a solution. Problem is that I can't ship a single certificate with the appliance image and have all everyone connected with it since openvpn will not allow more than one session per certificate.
Another issue is isolation between the VPN clients so that one client won't be able to connect to the other. how can that be achieved. Thanks