We deploy the Cisco VPN client as part of a Windows XP Ghost Image.
In order for the VPN to work, we do the following:
0. Disconnect LAN cable.
1. Set MTU to 1300 and restart.
2. Set MTU to default and restart.
I assume this issue is encountered becasue of the way the VPN miniports are "instlled". This step occurs during the initial PnP.
Perhaps the problem occurs becasue the LAN cable is connected during the driver install. The MTU speed is detected and applied to all interfaces including the dialup. In any event, could that be modified?
Is there a way to set Cisco's VPN settings in the registry.
Will setting Microsoft's MTU to a level around 1400 fix the problem?
http://support.microsoft.com/default.aspx?scid=kb;en-us;283165