There are couple of reason you want to know your Mac address. most obvious one is "you want to ensure your internet gateway does not block your Mac address, or you want to check if your Mac address is in allowed space". typical needs for any network related operation.

Here is how to use netcut to find your own Mac Address.

Once you click on "Change netcard" , select the netword card(adapter) , netcut will be able to show you the Mac addresss of the Adapter.

Note: the Mac address here will be the real MAC address , doesn't matter how have you been spoof your OS.

Underand what is Address resolution here : http://www.arcai.com/arcai-netcut-faq/a ... tocol.html