Fixed MAC addresses on Windows EC2 machines

Question

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?

Here is the problem:

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.

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.

But still, it's unclear what happens or if the underlying virtualization stack simply generates random MACs every time a machine is launched.

Of-course, I would love to hear about other workarounds if you have ideas..

Answer 1

You can use an EC2 instance in a VPC and attach an Elastic Network Interface to it.

ENI is like an additional network card that have fixed IP address (internal and external) and fixed MAC address.

More about ENI in AWS site.

Answer 2

Unfortunately there's no good workaround here. EC2 does not allow any manipulation of the MAC address on an instance.