VPN Using XP Servers and D-Link WBR-2310

OK, here is what I suggest you to do:

1. Remove port forwarding for TCP 47, you don't need this one (TCP 47 and IP 47 are not the same thing). Unless you also need IPSec, you may remove UDP 500 too.

2. Disable any firewall on both you Windows XP and try connecting again. If it works, then one of your software firewall is causing the problem. Then, enable one of them and try again. This will tell you which one is the culprit. If VPN still does not work after disabling both firewalls, then the problem must be in the WBR-2310.

3. Have you enabled PPTP Passthrough in your WBR-2310?

OK thanks for the results. This helps narrowing it down.

Are you trying to connect while both your XP computers are behind the same WBR-2130??

If not, let's try this. It may be a little tricky to do... Please let me know if you don't understand what I am describing here. The goal of the test is to exclude all "external" sources such as ISPs (some ISPs are blocking some types of requests to avoid their customer to use "commercial" services like hosting web sites).

1. Connect your XP Home computer directly into the WAN port of your WBR-2310. Give it a static IP address such as 200.0.0.2. Make sure the WAN link light on the WBR-2310 is on. If does not come on, you may need a cross-over cable.

2. Set the WBR-2310 to use a static IP address on the WAN interface, such as 200.0.0.1. Make sure to write down the current WAN configuration because you will need to set it back once the test is completed.

3. Try connecting your VPN on the XP Home by using 200.0.0.1 as your destination. If it works, then all your components (XP Pro, XP Home and WBR-2310 are fine).

4. Reset your configurations: reconnect the WAN port to your modem, set the WAN IP settings back to what it was and put your XP Home back to automatic IP or what ever it was set to.

Your VPN connection WILL indeed fail if you try to connect while both computers are bethind the same router, no matter if it is wired or wireless. This is due to the fact that the client (XP Home) will receive an IP address in the same subnet as the one it already have (source and destination network are actually the same one!)

Leave your setup as it is right now and try from another location. Trying from your home may actually be the best option. Public WiFi accesses like the one offered by bars or bistros may have restrictions that prevent the use of PPTP.

You are absolutely right, the subnet must be different at your home than at work. If it is the same, it is usualy easier to change your home network than the corporate one... I am sure you see why. ;-)

Just so you know, following the "best pratices", anyone should always change the default LAN IP configuration of any router.

You are also right about the PPTP Passthrough.

Have you tought about a SSL-VPN solution? It does not involve opening firewalls with strange protocols such as GRE.

I use a great product called SSL-Explorer. It allows you to browse Windows file share, publish web application, connect through RDP and more, all front the comfort of a web browser. It removes the need of configuring a PPTP connection on the remote computer. This is a commercial product but you can get a 2-user licence for free.

I think you should take a look at it.

Beware of opening an FTP over the Internet. I used to do that and I quickly ended up with a lot (1000 hits in an hour) of brute force attack trying to crack the Administrator password.

SSL-Explorer supports WebDAV. It allows to map a drive in a windows workstation to a remote server using HTTPS.