My first little tip for Windows Server 2012
I recently had to figure out the hard way that although the latest Windows versions bring with them support for newer hardware out of the box, you better not always rely on those drivers.
That said, a new HP ProLiant server had trouble to get connectivity to a tagged VLAN with it’s Broadcom chipset. The driver settings gave you the option to enter a VLAN ID, but it didn’t seem to honor it.
Proof was that as soon as original Broadcom drivers were installed the VLAN was accessible!