I currently have a very simple network with 3 client PC's all running WinXP and a Windows 2003 server. All are connected to the network through an ethernet hub 10mbps. The server has a Cable Modem connected to an USB port and is sharing the Internet connection with basic ICS.
Server has no other roles at all, no DNS, AD, IIS, etc.
The thing is I'd like to also share the Internet through the modem (sever's modem) because there is this manufacturing machine that only has a 56k modem and needs to download some firmware over the Internet.
At first glance, it would be easier to use RAS and NAT services but if I enable these I'd also have to setup a DNS service to forward queries, and last time I did my ISP complainted because our hosting company (hosting the webpage and the DNS name mycompany.com) complainted to them, saying that an IP (mine) was attempting AD synch or something to their name servers (at that time, I gave my server the hq.mycompany.com domain). Now, I chose that domain that time just by convention. I could have used nonexisting.com but it's just out of standards (company's), and management is tight on that kind of stuff.
So, the points go out to whoever gives me the ideal configuration, (less hassle) which, ideally would be sticking to ICS but I don't think it will also share its basic DHCP/DNS-Proxy through the modem