MAC Address not saving


I am installing a new box with freepbx to replace my old trixbox and have hit a snag that I can not find any solution to in the forums.

I am running two separate network cards so that I can use a separate network for my sip and IAX trunks.

I would like to use the Mac Address: in System Admin -> Network Settings but when I add it it does not seem to save.

When the box reboots it seems to randomly swap which card is etho and eth1

I am running
Asterisk (Ver.

Thanks in advance