We are experiencing an issue with our users vpn-ing in using windows xp / 02 data cards and windows vpn. We decided to use l2tp as pptp was causing RAS issues on ISA 2004 - server 2003. We havent really got time to troubleshoot this so the work around was to use a pre shared key with l2tp/ipsec. We are building another isa server to replace this one. However every so often we cant connect in. If we put the same pre shared key in again on ISA it works again for a while. Initally I thought this was caused by a reboot but I no longer think this is the case. Any ideas.TS GURU

Hello, Thank you for your post here. From your description, the L2TP VPN connection with PSK fails on the ISA server. To effectively troubleshoot the issue, please answer/ collect the following questions/information: 1. What is the error message when you attempt to connect the L2TP connection with PSK? You can also check whether there is any related the Event logs on the ISA server. 2. You can also collect the MPS report on the ISA server for further investigation and upload the CAB files to Skydirve (you may send the URL to me at v-mileli@microsoft.com for troubleshooting). Microsoft Product Support's Reporting Tools http://www.microsoft.com/downloads/details.aspx?familyid=cebf3c7c-7ca5-408f-88b7-f9c79b7306c0&displaylang=en Troubleshooting VPN over IPsec http://technet.microsoft.com/en-us/library/bb794765.aspx If you have any questions or concerns, please do not hesitate to let me know.

1. What is the error message when you attempt to connect the L2TP connection with PSK? You can also check whether there is any related the Event logs on the ISA server.On the client the VPN connection hangs on varifying username and password and watching the eventlog I recieve a Rasman eventid 20209 - 'A connection between the VPN server and the VPN client **.***.***.*** has been established but the VPN connection cannot be completed. The most common cause for this is that firewall or router between the VPN server adn the VPN clietn is not configured to allow Generic Routing Encapsulation - GRE protocol 47.......'Further testing over the weekend: I can connect using either protocol PPTP or L2TP over my home wireless but not using 3G. Although we tested all the 3G connections at head office before we deployed them. This affects both Vodafone and O2 3G so I assume this is something thats occured on our ISA server. Not sure why this would only affect 3G though.More info: I started to use L2TP after we had problems connecting using PPTP over 3G. The L2TP was the work around whilst we troubleshooted further. So that was the initial issue but now I think that L2TP has an intermittant issue.I will send you a reply to 2) later today. Thanks for your help.RegardsTS GURU

I have also notice that if I use a standard windows vpn with pptp I actually get a VPN 721 error but the Rasman event id 20209 is the same and still appears.TS GURU