I wonder if it's possible. Let's say I have a windows vista pc with a fast internet connection that uses dhcp server of the ISP (ip address always stays the same). This vista pc has a second network card (with ip 192.168.0.1) that connects to a switch. There are several other computers that are connected to this switch and utilize the windows vista pc's internet connection (using internet connection sharing). Well, when I tried to connect to the switch an ispconfig server (debian etch made according to the 'perfect setup'), I found out that I it doesn't work. Well, it displays a page only if I enter in browser it's internal IP (http://192.168.0.19). If I enter the external IP of the windows vista PC, I get nothing (cannot display the webpage). Of course I activated all the set of rules on the windows vista pc (manage network connections --> my internet connection --> properties --> sharing --> settings (select services running on your network that Internet users can access)) - where I put down all the ports and the ip of the networks'c computer (192.168.0.19 - the ispconfig server) I disabled windows firewall during the testing. But, as I said, it doesn't work. I wonder if the layout is impossible in principle, or is there some other way to make it work?
A vista PC is a really bad choice as a network router. You should consider to buy a normal router and dont use the vista PC for this. This will be easier to handle, work out of the box and is more secure.
Thank you, I'll do it, I understand that it's better in the long run. I was only wondering if the layout with a vista pc is possible in principle. By the way, for those who are interested - I've found a way for correct port forwarding that works on vista - it's a tiny freeware program called autapf. "out of the box" it correctly forwards all tcp connections (somehow I get errors on udp but I guess it can be fixed). Also there should be a lot of other similar programs But I'll get a router anyway.