Ok, here is a weird issue. I know this may not exactly be the right place to ask, but maybe it is a start. I apologize is this is too off topic. Here's the deal.
I have a Windows 2003 server which is an active directory domain controller and dns server. This server is behind a Zyxel ZyWall 5 firewall which is then behind an Edgewater firewall before the cable modem.
On the server, I have set up an incoming network connection to be a PPTP VPN endpoint. This works great from inside the LAN, I can make a VPN connection from a windows machine or from my T-mobile G2 (over WiFi in the LAN) just fine.
Ok, the cable modem has an external IP address which I know I can reach because my port forwarded, firewall-rule-allowed Remote Desktop gets through to this server normally. I have set up rules and port forwards in both firewalls for VPN as follows:
**Edgewater firewall has a checkbox for PPTP Passthrough and IP address field to pass through to. I set that field to the ZyWall's external address 10.10.9.xxx (which in within the Edgewater's LAN DHCP range)
**Edgewater firewall has a port-forwarding rule sending traffic from ANY on port 1723 allowed/permitted to the IP address of the outside of the Zyxel (same 10.10.9.xxx) at port 1723.
** ZyWall firewall (external address of 10.10.9.xxx) has port forward set to send ANY on port 1723 to the IP address of the 2003 server on its LAN (192.168.110.xxx)
** ZyWall firewall has port-fowarding rule sending traffic from ANY on port 1723 allowed/permitted to IP address of 2003 server on its LAN at port 1793
This whole setup works just fine when I establish a VPN connection using my G2 from on the WiFi (inside on the LAN) as well as with WiFi disabled, forcing it to use my cellular connection/data plan (forcing the connection to come in from outside the LAN). I can establish the VPN connection and it completes the connection and authenticates normally.
HOWEVER, when I try the same thing using a windows machine (or a Mac) it will not authenticate and get me connected. I think it may actually be getting to the 2003 server, but it seems to be failing the authentication. I using the same username/password on the G2 as on the windows machine. I am completely baffled as to why I can get in with Android but not with windows (neither Vista, XP nor 7 or macbook).
Any clues anyone? Or ideas where else I can look for help?
Thank you for any help you can give!
