All,
 I have a web site that produces reports based upon user inputs in to a web page (queries a backend DB) using classic ASP and crystal reports. If the report takes over 30 minutes to run the firewall that sits in between the client and the web server drops the connection as it has been sat idle, so the report never gets displayed to the user. To avoid this I need to use some sort of keep alive, either HTTP or TCP. 

The web server in Windows 2000 on IIS 6. I've created the registry keys in Windows for the TCP keepalive (and disabled the TCP offload features in the network card which I've heard can causes issues), however IIS doesn't seem to use this by default. I did download and test on the server a socket tester called TCP/IP Builder (www.drk.com.ar) which allows you to turn on and off the keepalive which works fine so I know the server can send them.

Does anyone know how to force IIS to use TCP Keepalives as I'm presuming that it must be 'enabled' for IIS ?

thanks!