En0 MAC Address

Hi,

I'm trying to work on a script that automatically changes the mac address because I am currently doing some work with a Unix based DNS, DHCP, and ePolicy Orchestrator. The script currently works with my airport card or certain occasions. However, with my Ethernet (en0) nothing happens and I've used ifconfig lladdr and ether and both seem as if they go through, but the address does not change at all. Has anyone figured out how to change the MAC address for en0? Any help will be greatly appreciated and would help me tremendously with my work.

Regards