How to change MAC address

Wikipedia defines MAC Address as :

A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model.

MAC address is a 6 groups of two hexadecimal value separated by ':' ,  assigned to the network interface card. The form of the addressing is known as EUI-64.  MAC Address are assigned by the manufacturer and therefore are unique for all the interface cards. Therefore MAC Address of a NIC is its identity. Its writted in a read only memory of the device.

If you are curious enough then you might want to find the mac address of your NIC card if its so then open your terminal and hit the command ifconfig interface . For my case the result is as follows:

[paras@c2w ~]$ ifconfig em1
em1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.10  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::725a:b6ff:fe08:cb3f  prefixlen 64  scopeid 0x20<link>
        ether 70:5a:b6:08:cb:3f  txqueuelen 1000  (Ethernet)
        RX packets 51281  bytes 39148048 (37.3 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 52656  bytes 12896736 (12.2 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 16  

Here the mac address is the ether value which is 70:5a:b6:08:cb:3f  for my Ethernet card em1. You will see more of this on the video attached below. Similarly for my wireless card the mac address is highlighted as follows:

[paras@c2w ~]$ ifconfig wlan0
wlan0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
        ether 00:17:c4:c2:92:d3  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

Because of this reason, MAC address being unique for each network device, MAC Address can be used as a security measure too. For example in a network mac address is extensively used for security measure. Like for a Local Area Network port security is obtained by the use of MAC address. Not only this, wireless networks are secured by the use of MAC filtering.

However, hackers are those who want to go beyond the security system. They come up with some way out to  hack these security system. And yes, hackers have been able to figure out the trick in tricking these systems by use of some applications to change the mac address. Here in this video attached it has a demonstration how we can trick system to bypass the security measures implemented using MAC Address of a device.