How to change MAC address in linux?

First find the physical MAC address of your machine by running the following command :

$ ifconfig -a | awk '/HWaddr/ {print "interface: " $1 "/t MAC: " $NF}'
interface: eth0/t MAC: 4e:97:0e:52:29:13
interface: wlan0/t MAC: 02:ec:b4:e1:dc:31

The hexadecimal numbers in blue denote machine's MAC address.

Now, login as root in Linux or use sudo before each command and execute it. 

# ifconfig eth0 down
# ifconfig eth0 hw ether 3c:97:0e:11:21:71 
# inconfig eth0 up
# ifconfig eth0 | awk '/HWaddr/ {print "interface: " $1 "/t MAC: " $NF}'  

I have changed my Mac address to  "3c:97:0e:11:21:71".

Note : This is the temporary change. Once you reboot your machine, the operating system will change the MAC address to the default.