I am running Small Business Server on three machines. The server machine has a single NIC connected to a LinkSys Router, and sharing an ADSL connection with the modem connected to the router. I want to enable ISA Server, but the installation routine tells me I need a second NIC to make this work. I have a second NIC in the machine, not connected to anything at the moment. My question is undoubtedly silly, but what do I connect the second NIC to - do I use a vacant port on the router? The two client machines are also connected to ports on the router. Help, and thanks in advance.