RRas Behind linksys

I am wondering if it is possible to setup a vpn RRas behind a linksys broadband router. I have the correct ports forwarded for PPTP. Have a policy setup to allow Nas-type vpn and a security group. Account Dial-in is setup to allow per remote access policys. Only have one nic in test server connected to internal switch. Public Side address is on the Wan interface of broadband router.
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http://www.techexams.net/forums/viewtopic.php?t=21257
Used superscan 3.0 I believe to scan.
Isp is comcast
Make sure you are also allowing linksys to pass VPN connections through the router. It will look like this in your linksys router: