Windows 7 - L2TP with preshared key?

Asked By PerSalm on 09-May-07 10:40 AM
I have to connect to a L2TP VPN using a preshared key. This works well with
Windows XP clients, but it doesn't work with any Vista clients.

In Vista I get an error 789 when the connection fails. I have tried the
advice I found about enabling NAT-T and enabling weak encryption for L2TP
without any change.


PerSalm replied on 10-May-07 05:38 AM
I can report that this was solved by the sysadm at the server side who
applied some patches on the server.

ramachandran replied on 12-May-07 01:29 AM
Hi Per,
Are you aware of what these patches that your admin applied on the
server? The info will help us help other customers like you who are
experiencing a similar problem. You can send me this info to

PerSalm replied on 14-May-07 07:03 AM
Just so that anyone can find the same info I repeat the solution here:

The VPN server/firewall used at my clients site is a Clavister product. The
version that they upgraded to make the connection work for me is 8.80.02.
Last Friday a version 8.81.00 was released that also should contain the same
The administrator also tells me that customers running version 8.60 that
doesn’t have support agreements can get the same fix by installing version

/Per Salmi