interface MAC addresses

[romand]

Where does opnsense store the mac address of the interfaces of the firewall.  I ran into issue after moving the
disk from one machine to another.  The mac addresses of the interfaces on the new hardware were changed to those of the old hardware.  Is there a file that stores this information that I can change/edit to reflect the new
addresses?  Also what is the difference between the ether address and the hwaddr?  Should they not be the same?
What issues can I run into if they are different?  I have tried changing the MAC address in the gui and on one interface it changed both the ether and hwaddr on another it only changed the ether address. Any help would be greatly appreciated...