For the K1000:
Navigate to: Settings>Support>Troubleshooting Tools
Or, if you have organizations enabled, it will be: System>K1000 Settings>Support>Troubleshooting Tools
Once there, click on Edit Mode. Select ifconfig from the drop-down menu and click Test.
In the window that pops up, the entry by "ether" will be the MAC address.
For the K2000:
Select ifconfig in the drop-down and click Test.
You may see two entries for "ether" as there may be 2 active network connections. Those are the MAC addresses.