View network settings:
ifconfig
Temporary change of MAC address (until system reboot):
sudo ifconfig eth0 hw ether XX:XX:XX:XX:XX:XX
Where eth0 is the name of the network interface, and XX:XX:XX:XX:XX:XX is the MAC address.
Permanent MAC Address Change:
Create any file in the /etc/network/if-pre-up.d/ directory, for example mac:
cd /etc/network/if-pre-up.d/
touch file mac
sudo nano /etc/network/if-pre-ud.d/mac
Add the lines to it:
#!/bin/sh
ifconfig eth0 hw ether XX:XX:XX:XX:XX:XX
The nano editor uses the keyboard shortcut Ctrl+O to save and Ctrl+X to exit.
See also my article:
Configuring the Network in Linux