
For many systems administrators, choosing and managing a VPN system is often quite a headache. Inflexible clients, servers, and protocols often prevent VPN's from being smoothly integrated into an already functioning network. The fact that many VPN clients are installed on users' home computers, well out of the reach of the systems administration team, often means that troubleshooting and upgrading VPN systems is time consuming and a struggle for both admins and users.
OpenVPN can operate in TAP mode, which is a virtual ethernet connection. Anything that will run across ethernet will run over openvpn (although I don't think its the most efficient way). I have my VPN handing out ips via dhcp.
so, yes it will do IPX.