I'm having a few problems with XP and VPN. We have an industrial ethernet subnet which we would like to join to our company network. This will enable me to locate problems on machines in the comfort of my office rather than having to drive / walk to them.
To improve the network security we are trying to use a D-Link DFL-200 to seperate the two subnets. All the subnets are on the same domain. I've set up a test setup in the office to see if I can get it to work. We thought that the most secure route we could could go down was the VPN route. I've managed to get a PPTP connection to the DFL-200 using the win xp vpn client, however when I make the connection my PC seems to grind to a halt. If I try to open a program it can take up to 5 minutes to start. If I log on to the local machine instead of the domain, the PC runs ok. So I'm assuming it has something to do with the domain settings. Does anyone have any clues as to what to do?
Also once I'm connected via VPN on the local machine I'm sometimes unable to ping the XP PRO2 machine? When I'm connected via vpn and the vpn server gives me an IP address of (where x = 1 to 10) and gateway of the same address id this correct? Or is this why ping doesn't work?

For info the xp pro2 machine is a SCADA PC that is used to display the telemetry of the machine and to provide data management. Also connected to this subnet are PLC's (programmable logic controllers) that used to control the machine. The SCADA PC has to be connected to the domain to recieve virus updates, it also sends production reports to the server.

Some of the settings that I've used in the Office setup are:

Xp Pro1 IP:
VPN PPTP Settings: Host: connect using a username and password

VPN IP: by dfl-200)
VPN MASK: by dfl-200)
VPN GW: by dfl-200)

D-Link DFL-200 WAN IP:


XP Pro2 IP:

Any help or ideas would be gratefully appreciated.



Hello Rich,

I would like to help you work on this, but need a graphical network diagram to sink my teeth into. If you can make a drawing and scan it, and attach it as a .pdf or something, I would be happy to look.