VPN set up but can’t access anything!!!

Hi!

This is a rather stupid question, but I really can’t find a way to make it work.

I have established a VPN connection between a windows XP pro server and a windows XP pro client. I had to work DDNS because of the dynamic IP of the server.

The point is, the connection is established, but I can’t access a single resource of the server!

I believe that I might have forgot to do something, but I have no idea what.

Any suggestions??

Thanks