Q. How can I make it so that non-primary IP addresses on a network adapter don't register in DNS with Windows Server 2008 R2?

A. In Windows Server 2008 R2, the behavior of the non-primary addresses on an adapter changed so that all IP addresses register with DNS instead of just the primary IP address. Microsoft released a hotfix for Windows 7 and Windows 2008 R2 that allows you to configure additional IP addresses on an adapter without them registering with DNS. It uses the skipassource=true flag. You need to:

netsh int ipv4 add address   skipassource=true