VPN Setup using Windows 2003 and Dlink DSL 504

[paulmulrainey]

I am currently trying to set up my Windows 2003 Server for VPN Access. Hope someone can help, heres a little of the history,

server set up with LAN static IP 192.168.0.100
Router set up with LAN static IP 192.168.0.1 also has public static IP from ISP

The Win2003 Server is DC has DHCP,WINS,DNS(used internally)Terminal Services,IIS,POP Service and VPN.

I have 1 client XP machine on LAN which get IP from Server and can browse the Internet through router fine all seems well :->

the XP machine can authenticate with the VPN server on Windows 2003 using PPTP over the LAN (I cant see any apparent use for that but it works none the less)

I have port redirection setup on the Router
redirecting ports as follows

TCP 80 for Web Browser
TCP 3389 for Terminal Services Web Client
TCP 25 for SMTP server
TCP 100 for POP server
TCP 1723 for VPN
UDP 1701 for VPN
UDP 500 for VPN
UDP 4500 for VPN

all above ports redirect to windows 2003 Server and from my own home machine(Windows 2000 Pro with ADSL connection) I can

Connect to the server using Web Browser,Outlook and TS Web Client

I have read about GRE 47 protocol is this an issue. Hope some genius out ther can shed some light

Many Thanks

Paul