title: Fixed MAC addresses on Windows EC2 machines
body: <p>On Windows machines that we own it's possible to change a MAC address to a pre-assigned value. But is it possible to set the MAC address on EC2 Windows machines to a pre-assigned value?</p>
  
  <p>Here is the problem: </p>
  
  <p>We provide a virtual lab/training/evaluation environment that runs off Amazon EC2. Every so often a customer wants to run licensed software (that they own!) in the cloud, but the licensing component requires a fixed MAC address to exist. </p>
  
  <p>But it's unclear what happens in EC2 if we tweak with the MAC address, especially after a reboot or snapshot of the machine. One big issue I see is that if we take a snapshot of a machine with a fixed MAC, and then launch multiple copies of it, then each copy will, in theory, have the same MAC address. Obviously a routing issue. </p>
  
  <p>But still, it's unclear what happens or if the underlying virtualization stack simply generates random MACs every time a machine is launched. </p>
  
  <p>Of-course, I would love to hear about other workarounds if you have ideas..</p>