The DNS search order is reversed on the DHCP client in Windows Vista or in Windows Server 2008 when you use dial-up or a VPN connection to connect to a Routing and Remote Access server
You use a dial-up or a virtual private network (VPN) connection to connect to a Routing and Remote Access server. However, the list of Domain Name System (DNS) servers that is stored on the Windows Vista or Windows Server 2008-based Dynamic Host Configuration Protocol (DHCP) client computer is in reverse order.
For example, when you connect to the Routing and Remote Access server, the DHCP server sends the DNS IP addresses in the preferred order:
However, if you view the TCP/IP protocol properties on the client computer, the DNS IP addresses appear in the following order:
This problem may cause excessive WAN traffic or poor DNS performance.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB958551.