Printed on Board
The network address of some Ethernet card is on a printed label on the back of the Ethernet circuit board.
EtherPeek
You can obtain the AG Group EtherPeek network monitoring application, which includes a utility called it GetMyAddress. This will also return the address of the Ethernet card.
MacTCP
Users who use MacTCP may be able to identify the Ethernet address by opening the MacTCP control panel and pressing the Option key when selecting the Ethernet Icon. For this to work you must be sure the caps lock key is NOT depressed.
Open Transport 1.1 or Later
If you are using Open Transport (version 1.1 or later), you can obtain the Ethernet address by opening the AppleTalk control panel and selecting Get Info from the File menu.
Apple LAN Utility
You can use the Apple LAN Utility to report the burned in address without being connected to a network.