Order of installation of Active Directory and DNS on Windows Server 2008 R2

This question relates to introducing Windows Server 2008 R2 Active Directory and DNS into a network for the first time. Currently, all our Windows desktops just belong to a workgroup, and we are using a Linux based DNS server that is built into our router.

Our plan is to create an AD forest consisting of a single Domain, which will house all of our desktops (about 40) and some other internal resources (printers, etc.). We are installing two Windows Server 2008 R2 computers to serve as domain controllers for the Domain. We also want to use the Windows Servers for DNS.

As there is a close inter-dependency between Active Directory and DNS, I am not clear what the correct order is for installing these server roles and migrating DNS. It seems to be a chicken/egg problem. At the end of the day, I want to set up AD, use AD-integrated DNS, and have the Windows Server based DNS replace our existing DNS server, including name resolution for non-Windows related resources on our network. Any recommendations on best practice on the order of steps to get there would be much appreciated.

Thanks!

It doesn't matter much. If you don't have DNS installed when running dcpromo.exe to promote a server to a DC, it will ask you if you want to install it and create all of the necessary zones automatically. If you already have it installed, it'll just create the zones as necessary. Personally, I always just run dcpromo and let it install DNS from there during a promotion, so that I don't have to deal with the extra setup wizard stuff that you go through when you install DNS on a member or standalone server.

The out-of-box configuration is set up for recursion when you install it this way, so you can point your workstations to it and it'll resolve external names as well as internal ones.