Real world sit. One subnet 192.168.0.0 goes to your switch to inet. One subnet 192.168.168.0 goes to internal LAN w/ SAN/NAS/Media server etc. You don't want your internal LAN to be seen by external inet LAN. Solution is to use two IP's "shimmed" on one NIC assuming that there is a physical route to both LANs. When you add multiple IP's to one NIC in Winderz now it uses the built in net shim to setup multiple IP stacks above the protocol layer. Used to be in the old days you replaced the M$ IP stack with another aftermarket or your own and installed a shim manually. Microslop has removed that now by using the std. shim they put into their stack to be able to change net settings without having to reboot (really crappy). Just make sure you don't allow bridged traffic between the two subnets....