I ran into this one recently with Exchange 2010 and SMTP Virtual Servers, whilst setting multiple IP addresses on a single network interface. In Windows Server 2008 R2, by default, all IP addresses assigned on a network interface will register records within DNS.   This can be problematic if you don’t wish to register particular IP addresses and want to limit this to say just the primary IP address (or combinations).  A  hotfix from Microsoft is available that allows the use of the NETSH command in conjunction with the skipassource parameter

Netsh int ipv4 add address <Interface Name> <ip address> skipassource=true

Here’s the original TechNet article.

http://support.microsoft.com/default.aspx?scid=kb;en-US;2386184

Mylo