A couple of months ago, I wrote a series of articles on Hyper Visor (more commonly known as Hyper-V), the new server virtualization component for Windows Server 2008. Since that time, I have gotten a several E-mail messages from people wondering why they can’t access their network from a virtual server. In this article, I will attempt to shed some light on the subject.
Assign a Network Adapter
The first step in making sure that a virtual server can access your network is to assign a physical network adapter to the virtual server. Ideally, your physical server should have enough network adapters installed that each virtual server can have a dedicated network adapter, but this isn’t a requirement. Virtual servers can share a network adapter with each other, and even with the host operating system if necessary.
With that said, open the Hyper-V Manager by selecting the Hyper-V Manager command from the server’s Administrative Tools menu. When the console opens, select the virtual machine that you want to add network support to, and then click the Settings link found on the Action pane. You should now see a screen that allows you to adjust the various settings for the virtual server.
Choose the Network Adapter option, as shown in Figure A, and then assign a physical network adapter for the virtual machine to use. As you can see in the figure, you also have the option of specifying a MAC address and a VLAN number for the NIC, but this is not a requirement. When you have assigned a network adapter to the virtual server, click OK to close the dialog box.
Figure A You must assign a physical network adapter to the virtual server.
Install the Integration Services
In the earlier betas of Hyper-V, it was necessary to install the integration services. In the current beta, the integration services are installed automatically for a virtual server that is running Windows Server 2008. This may or may not be the case for other server operating systems; I don’t know. In any case, I recommend attempting to install the integration services to see if they are necessary.
To do so, choose the Insert Integration Services Setup Disk from the virtual machine’s Actions menu. Next, start the virtual machine if it is not already running and open My Computer (on the virtual machine). At this point, go to D:\Support\AMD64 and run Setup.exe. Windows will either install the integration services or tell you that the integration services are already installed.
Install a Device Driver
The last part of the process is to install a device driver for the virtual machine’s network card. You won’t be able to use the device driver for the physical NIC. You’ll have to use a special device driver that’s located on the Integrated Services Setup Disk (which of course is nothing more than an ISO image installed onto your system’s hard drive by Hyper-V).
To install the network driver, click on the Start menu, and then right click on Computer and choose the Properties command from the shortcut menu. When the System Properties sheet appears, click the Device manager link. Look through the Device Manager until you find the Microsoft VMBus Network Adapter listed beneath the Network Adapters node, as shown in Figure B.
Figure B Virtual servers use the Microsoft VMBus Network Adapter regardless of what type of NIC is physically installed in the server.
Right click on the network adapter listing, and choose the Update Driver Software command from the shortcut menu. When you do, Windows will display the Update Driver Software dialog box. Click the Browse My Computer for Driver Software button, followed by the Browse button. Now navigate through the file system to D:\support\amd64\en-us, and click Next. Windows will now install the device driver. When the process completes, click the Close button.
In this article, I have explained that when you install a virtual server on a machine that’s running Hyper-V, the virtual server will typically not have access to the network. I then explained how you can assign a physical network adapter to the virtual server. I also showed you how to use the Integrated Services Setup Disk to install the integrated services if necessary and to install device driver for the virtual NIC.
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