is there any VPN program that handles client authentication, data encryption and ends in a tap interface for every authenticated client?
I need 1 shared UDP port (VPN service port) to which clients are connecting with VPN protocol and and I need that every authenticated client ends up in its own tap interface.. this allows me to set up firewall, routing, different dhcp server, ... for every client connected to VPN concentrator separately.
OpenVPN is not an option because I don't know to setup 1 external port -> separate tap interfaces. I don't want to do routing or whatever filtering in the VPN daemon, this is kernel's job.
If it doesn't exist I'm going to write my own app (will be GPL or so, of course).