How do I diagnose why the VPN client won't connect

[Guest]

Hello.
Are the logs somewhere (on my client machine) that will tell me the error
message for why the Vista VPN client (Vista Business) will not connect to my
University's VPN? I'd look to figure out what is going on, but Vista just
says failed to connect.

Thank you,
Daniel

 

[Synapse Syndrome]

I had a problem with a VPN connection on my Vista laptop and couldn't
figure it out for a while because I knew everything was set up correctly.
Then I found MS KB 953795, which I've expanded on here, http://techierambl
es.blogspot.com/2008/12/vpn-connection-problems-in-windows.html. That
solved my problem. Anytime I tried to connect it would fail immediately,
and it turned out it was because of some corruption in the PPTP and L2TP
built-in VPN files on the laptop. The main thing to watch is where the
connection attempt fails. If it happens right away, it's possible that you
had the same problem I did, but there are a lot of other possibilities too
such as a misconfigured connection. If the status changes to verifying
username/password, then you know there is connectivity. If it fails after
that point, it's most likely just an incorrect username or password. Once
it gets past the verification stage you shouldn't have any other problems.

*Note, I strictly have dealt with PPTP user VPNs. I have experience with
IPSec and L2TP only through IPSec tunneling for site-to-site connections,
not for end users. If you're connecting to an IPSec VPN then I have no
idea if anything I said is going to help. Good luck either way

What VPN software are you using? I have never been able to get the built-in
Windows one to work. I tried some a web-based one for a while, but now I
use OpenVPN (SSL).

ss.

 

[Sameguy]

I have Fortigate firewalls and they have built-in support for PPTP and IPSec
VPNs. It's really nice because it's not an extra licensed feature like some
firewalls I've seen. Anyway, I have the VPN connection set up on the
firewall, and then use the Windows client to configure the connection. It
works great for the PPTP. It has SSL VPN support built in too, but they need
to do some work on it. It has a tendency to randomly crash.