Use the commands below to obtain your machines MAC address.

>> OS X

ifconfig en0 | awk '/ether/{print $2}'

Notes: A typical mac may have more than one active network interface. For example, one for Ethernet and one for Wireless. We always want the interface labeled en0.

>> Linux

ifconfig eth0 | awk '/ether/{print $2}'

Notes: Linux is very similar to OS X, but interfaces generally eth instead of en.

For Linux users without an active network, please use:

ifconfig | grep HWaddr

>> Windows

ipconfig /all

Windows users typically have several interfaces, the one we want is the first physical device adapter. When we run the above command, look for the first instance of Physical Address. The value we want is a set of 6 octets separated by dashes on the same line.