You can view the original tool here.

This script will generate a random MAC address for your use. If you select a Vendor, it will generate a random MAC within the address range owned by that vendor. The Random option will only generate random MACs that are valid and within OUI registered ranges. Really Random doesn't care whether the MAC is in a registered range or not, and just generates completely random MACs.

# of MACs to generate:

Vendor:


I started working on a CLI version of this script as well so that it can be called from bash/batch scripts, etc.