Captive portal on pfsense when dhcp is managed by win2k8?

[mcbrain]

Can I do this?

When I enable captive portal now, it either hangs the internet connection for the users (no logon screen appearing), or pages start loading, and do not complete.

My bet is a DNS problem. But shouldn't that get handled by my 2008 server?

[buraglio]

Can the 2k server resolve addresses?  You can have dhcp and dns managed elsewhere without problem, but the proper holes need to be poked to allow for it. 
You could always try another DNS server like opendns, poke a hole through for it and see how that works to take 2k out of the equation.

nb