I have a Windows 2003 IIS 6 server with 2 NIC's, one on Subnet A and the other on Subnet B. All ports have been opened on the firewall between Subnet A and Subnet B. There is only one website configured with an IP address from Subnet A. Clients on Subnet A can access the website although clients on Subnet B can not access the website. If I remove the second NIC (the one on Subnet B ) then Subnet B can access the website on Subnet A. Although I can't use this configuration because of other applications requiring the server to be dual homed. How can I allow clients on Subnet B to access the website on Subnet A when the webserver is dual homed?

How can I allow clients on Subnet B to access the website on Subnet A when the webserver is dual homed? Without knowing how you've got things setup in more detail the only thing I can tell you is you need to route the http traffic from Subnet B to Subnet A the same way it went when you removed the Subnet B NIC. So examine your setup. Figure out which way the traffic flows when you've removed the Subnet B NIC and emulate that. It may be as simple as changing the gateway IP on the Subnet B clients, or as complicated as changing some routing in your router and/or the multihomed server itself.