We have a T1 from our ISP to a Cisco 1721 router. It has a connection to a hub and it then connects to our Small Business Server 2003 box. The SBS 2003 box does have Microsoft ISA installed. When I plug into the hub and use and one of our external addresses assigned by our ISP, I am able to successfully connect to our Microsoft VPN via PPTP. When I attempt to connect from the other side of the Cisco 1721 it fails. What do I need to do to have the Cisco 1721 forward the appropriate VPN traffic to our server?