Have just setup SBS 2011 and enabled the VPN functionality.
Here is my setup. The server currently sits behind a firewall (Vigor 2830) on my LAN. My LAN ip's 192.168.1.x with the interface to the firewall at 192.168.1.87. The SBS 2011 sits behind the firewall at 192.168.12.4 with its gateway being the firewall at 192.168.12.3. The SBS connects to the internet fine, RWW works fine etc, exchange works fine. Port 1723 is open on the firewall.
The VPN however will not connect. If I create a new VPN connection from my PC pointing at 192.168.1.87 with a username and password of a user on the SBS 2011, I get verifying username and password then Connecting to 192.168.1.87 using WAN Miniport SSTP, then its asks to Reenter the username and password again saying the orginal was not correct... but it was I have used several usernames and password and reset them... they are definitely correct. The users are enabled for VPN connection too. The SBS DHCP seems to be issuing an address as well.
How can I troubleshoot this? I Cant find any sensible logs? Is this because my PC is on 192.168.1.x subnet the same as the untrusted interface to the firewall?