Changing MAC address under Linux Command Line

[1] Ref

$ ifconfig -a | grep HWaddr
eth0  Link encap:Ethernet HWaddr 00:80:48:BA:d1:20

# ifconfig eth0 down
# ifconfig eth0 hw ether 00:80:48:BA:d1:30
# ifconfig eth0 up
# ifconfig eth0 |grep HWaddr

In Linux, Windows, Mac OS X, or a different operating system, 

changing MAC address is only temporary. 

Once you reboot your machine, the operating system reflects the 

physical MAC address burnt in your network card and not the MAC address you set.