Short for Media Access Control address, a hardware address that uniquely identifies each node of a network. In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sublayers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network medium. Consequently, each different type of network medium requires a different MAC layer.

The specific command used in Unix to find a MAC address varies depending on the version of the operating system. In Linux and in some forms of Unix, the command “ifconfig -a” returns MAC addresses.
You can also find MAC addresses in Unix and Linux in the boot message sequence. These operating systems display the computer’s MAC address on-screen as the system reboots. Additionally, boot-up messages are retained in a log file (usually “/var/log/messages” or “/var/adm/messages”).

# In order to change your MAC address just type the following:

$ sudo ifconfig eth0 down hw ether 0A:0B:0C:0D:AA:BB

Note: “0A:0B:0C:0D:AA:BB” is just an example, you should put there the disired MAC address

Note: bringing down the interface (sudo ifconfig eth0 down) and them changing the mac address (sudo ifconfig eth0 hw ether 0A:0B:0C:0D:AA:BB) did not work, instead i did all in one line as shown above

# Now bring the interface back up, and you are ready to go.

$ sudo ifconfig eth0 up