Microsoft Hyper-V – Change VMs MAC Addresses

This is a tricky one…

I found out that some of mine Virtual Machines in different host machines were getting the same MAC Address.

With some research I found out the problem was using the same image (WIM) for deployment, that has already Hyper-V role installed.
After a little googling I’ve noticed that this is a problem that a lot of people are complaining.

So…there are to approaches to take here:

Creating new images
When creating new images for deployment, just delete the following keys before sysprep the machine:

HKLM\Software\Microsoft\Windows NT\CurrentVersion\Virtualization\MaximumMacAddress

HKLM\Software\Microsoft\Windows NT\CurrentVersion\Virtualization\MinimumMacAddress

Already Installed Machines
For this one, run the vbscript published at TechNet Forums:
Script to reset VM MAC Addresses 

After running the script don’t forget to restart the virtual machines.

 

Hope this helps some people like it really helped me!

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