Configuring NICs in Hyper-V
At my day job, we currently run Windows Server 2003 with Virtual Server 2005 R2 SP1. One on the things we do is setup a “Shared Virtual Network” in which the guest virtual machines use a dedicated NIC separate from the one the host uses. To do this we take one of the server NICs and deselect all the network components (i.e. Client for Microsoft Networks, Network Load Balancing, File and Printer Sharing, TCP/IP) except for Virtual Machine Network Services. This NIC doesn’t not get an IP number and only allows pass through traffic from the guest virtual machines.
So, how do you do this in Server 2008 wth Hyper-V and Server Core?
When Hyper-V is configured with a Virtual Network that is connected to a physical NIC (External) the network components on the physical NIC are all unselected except for the “Microsoft Virtual Network Switch Protocol” be default. A new virtual NIC is created to allow the host to communicate with the VMs via a virtual switch. This virtual NIC on the host can be disabled and the VMs can still access the physical network.
So, in Server Core the only thing that should need to be done in a multi-NIC situation is to disable the new virtual NIC that gets created because by default it is setup for DHCP and will get an IP number from a DHCP server if available. In addition the NICs could be renamed to reflect if they are assigned to the host or the guests. I’ll be testing this out in the coming weeks.
