change mac address

[LINUX]
ifconfig eth0 down hw ether 00:00:00:00:00:01
ifconfig eth0 up

[MacOS]
sudo ifconfig en0 lladdr 00:00:00:00:00:01
sudo ifconfig en0 ether 00:00:00:00:00:01

[BSD]
ifconfig xl0 down
ifconfig xl0 link 00:00:00:00:00:01
ifconfig xl0 up