When I installed AD a few years ago, I had to uninstall it, as I didn't have a static IP address. Maybe it works with a router, but I thik the jist of it is having a static IP address. I could be wrong, however, and if I am, will try it again.

I found that I didn't need a DNS, as I used my ISP for DNS services. I guess it depends on what you want to do. How many users do you have that need DNS service?