Hi
I'm having problems with the Smart VPN Client using L2TP over IPsec on Windows 7 & 8, connecting to a Vigor 2850

Not sure if anyone else has this same problem, but i have never been able successfully create an L2TP over IPsec tunnel. I follow the instruction correctly, allowing the VPN software to make the registry changes and rebooting.
When i setup the connection the 'Support NAT-T for IPsec tunnel' is always greyed out, even when i manually change the AssumeUDPEncapsulationContextOnSendRule registry setting to 0, 1, or 2 which changes the NAT-T mode. the connection always drops after about 10 seconds regardless of the setting.
In the Smart VPN connection statistics i can see the tunnel is made and i sucessfully get a DHCP address allocated from the server inside the Vigor 2850 network, i can even see the new route created in my routing table with that DHCP allocated address.
But i never get any traffic to pass over the tunnel and it will always disconnect after a short time.

Smart VPN v4.1.0.1
Draytek 2850 FW: 3.6.2_2471201


Thanks for the help

Anyone?
Does anyone else have this issue?