I believe you want to have remote access users connect to the pfSense box with a VPN and authenticate with Active Directory....if so try OpenVPN with reference to this forum topic:
http://forum.pfsense.org/index.php/topic,4105.0.html Please let me know if this is not what you are looking for. -- Curtis LaMasters http://www.curtis-lamasters.com http://www.builtnetworks.com
