VPN to firewall or passthrough

After I did more reading and understanding, you would use a pass-through when you have remote users connecting and there location maybe different. A vpn to the firewall would occur when you have a predefined end point from the remote user. So for most instances a pass-through connection would be made with vpn server on the recieving end.

What is a VPN in this regard? IPSec? OpenVPN? L2TP (a VPN protocol according to Microsoft)?

What kind of firewall/server are we looking at?

I am mostly/only familiar with IPSec, so I'm going to comment on that regardless...

Configuring IPSec is not trivial on Windows XP; I am in the process of configuring some client machines on heterogenous networks, and while IPSec works fine once you get it going, doing so is quite non-trivial, due to lack of documentation and lack of useful log files (let alone error messages - not even a fatal exception this time!) - I usually work with the Windows log (oakley.log) open, a remote login to the VPN server showing the logs there, and sniffers on both ends.

All in all, to answer your question, it can be done. However, one must install the WinXP Support tools from the Microsoft page, and optionally ipsec.exe. Plus, potentially, a certificate.

Though, admittedly, my decision to rip out L2TP and PPP by using ipsec.exe (see

Windows should also support OpenVPN, though I do not have personal experience or ever witnessed OpenVPN in operation.

Joachim