David Schwartz <davids@webmaster.com> wrote: > There are other ways. It depends. I haven't tried this, but maybe you can do this: Machine A is your filtering machine Machine B and C are Windows boxes Your subnet Mask is 255.255.255.0 B has IP address 10.0.2.2 default gateway 10.0.2.1 C has IP address 10.0.3.2 default gateway 10.0.3.1 A is configured with three IP addresses against its single interface card: 10.0.0.1, 10.0.2.1 and 10.0.3.1 B and C are on separate network addresses, and the only way to communicate with each other is via the filtering gateway. I haven't tried any of this stuff, and I don't know off the top of my head what changes would need to be made to the gateway machine, but I am sure that you can assign more than one IP address to a network interface card, so I think you are half way to a solution. Mark. -- Mark Hobley 393 Quinton Road West QUINTON Birmingham B32 1QE Email: markhobley at hotpop dot donottypethisbit com http://markhobley.yi.org/