Debugging a VPN

[Jay]

I tried to set up a VPN on a PC running Windows 2000 server (giving other users access to files on
this server) but I couldn't access it from other PCs. I set up the Norton firewall to allow
communications, but no joy.

Any tips on debugging the problem?

Also, can I debug it by trying to connect to the VPN on the same server (so that communications go
out to the internet then go back in to the same machine)? If not, my biggest problem is how to try
things out, since I don't have access to another PC with an independent internet connection.

 

[Pegasus \(MVP\)]

I tried to set up a VPN on a PC running Windows 2000 server (giving other users access to files on
this server) but I couldn't access it from other PCs. I set up the Norton firewall to allow
communications, but no joy.

Any tips on debugging the problem?

Also, can I debug it by trying to connect to the VPN on the same server (so that communications go
out to the internet then go back in to the same machine)? If not, my biggest problem is how to try
things out, since I don't have access to another PC with an independent internet connection.

Set up an external WinXP Professional PC to act as a Remote
Desktop PC. You can then try your VPN session from that
PC under an RDP session.

 

[Jay]

Thanks for the tip.

Just one question, isn't a Remote Desktop PC effectively using a VPN (although this fact may be
hidden from the user)? So if I have a problem with seting up a VPN (eg due to an incorrectly
configured firewall which I suspect to be the case with the problems I've had) then I might also
have the same firewall problem with remote desktop.

Jay

I tried to set up a VPN on a PC running Windows 2000 server (giving other users access to files on
this server) but I couldn't access it from other PCs. I set up the Norton firewall to allow
communications, but no joy.

Any tips on debugging the problem?

Also, can I debug it by trying to connect to the VPN on the same server (so that communications go
out to the internet then go back in to the same machine)? If not, my biggest problem is how to try
things out, since I don't have access to another PC with an independent internet connection.

Set up an external WinXP Professional PC to act as a Remote
Desktop PC. You can then try your VPN session from that
PC under an RDP session.

 

[Pegasus \(MVP\)]

While Remote Desktop ***can*** use a VPN, it can also
stand on its own feet. Here is what you need for a Remote
Desktop connection to function:
- You must know the host's external IP address.
- The host's internal IP address must be fixed.
- The host's router must forward port 3389 packet to the
host's internal IP address.
- Remote Desktop must be enabled on the host.
- Your account must be authorised to use Remote Desktop
on the host.

In your case the "host" is your external Windows XP Professional
workstation which you can use to test your VPN.

You can test the basic connectivity of VPNs and RDPs with telnet:

VPN: telnet host_address 1723
RDP: telnet host_address 3389

 

[Jay]

Thanks for your help, that's good information.

Jay

While Remote Desktop ***can*** use a VPN, it can also
stand on its own feet. Here is what you need for a Remote
Desktop connection to function:
- You must know the host's external IP address.
- The host's internal IP address must be fixed.
- The host's router must forward port 3389 packet to the
host's internal IP address.
- Remote Desktop must be enabled on the host.
- Your account must be authorised to use Remote Desktop
on the host.

In your case the "host" is your external Windows XP Professional
workstation which you can use to test your VPN.

You can test the basic connectivity of VPNs and RDPs with telnet:

VPN: telnet host_address 1723
RDP: telnet host_address 3389