I have an OpenVZ VPS with ubuntu 9.04 installed. I have successfully installed and used OpenVPN with this VPS, but I need one of the 3 protocols mentioned in the title for access via. iPhone. OpenVPN isn't supported on the iPhone as far as I have discovered.

I haven't been able to get any of the above protocols to work. I've tried:

openswan - Fails because of some kernel support isn't available.
pptp - Fails because ppp doesn't appear to be available. I've tried to mknod /dev/ppp, but it just sort of sits there for a while then dies saying it can't establish the ppp connection.

Has anyone managed to get a VPN connection with an iPhone to work under an OpenVZ VPS? Any tips would be greatly appreciated.