I'm confused on how to initially set up OS X SERVER. I have an airport extreme that connects to the internet with 2 DNS servers provided by my ISP. I DO NOT have a domain name registration and I"m not that interested in getting one because I don't need internet access to the server. So in the "domain and dns" installation what should I put? Do i enter the local ip address for the router as the DNS and just make up any name for the domain??