Problem with “IP Address Already Assigned” in a Hyper-V Virtual Machine

6:49 pm in Hyper-V by Wim Matthyssen

In my third blog post I will tell you how to solve an issue you can get when setting a fixed IP address on a Virtual Machine (VM). Like you see in the screenshot below there is already another “Microsoft Hyper-V Network Adapter” with the same IP address assigned to the VM. Simply said this ghosted virtual network adapter (vNIC) has the same IP address as the one you try to set.

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This problem can have several causes. In most cases it occurs when you delete a vNIC with a fixed IP address and later on try to set it back. But it can also take place when a VM is not migrated properly between Hyper-V hosts or when a backup of a VM is set back to another host. Nevertheless don’t worry in this post I will show you how to repair this. You can fix this by uninstalling the ghosted network adapter. There are several ways to do this, one of them is by use of the registry but there is also a quicker fix. This one I will show you below:

1) First of all answer No to the question in the pop-up.

2) Now open up a command prompt with Run and type in cmd.

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3) Type set devmgr_show_nonpresent_devices=1, and press Enter.

4) Type devmgmt.msc, and press Enter.

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5) When “Device Manager” is open, click View, and then click Show Hidden Devices.

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6) Expand the Network adapters tree.

7) Right-click the dimmed network adapter, and then click Uninstall.

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8) Click OK to Confirm Device Removal.

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9) When the device is removed, set the IP address to the vNIC. This should work.

10) Finally check the right settings, by running ipconfig in a command prompt.

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As you can see the fixed IP address is set. This concludes this blog past. Keep tuned and I’ll be back soon.

Wim Matthyssen (@wmatthyssen)