In some situations you need to fake / change / spoof a MAC address of your network interface. macchanger Linux command does this job in no time. With this tool you can change your mac address of any Ethernet network device wired or wireless.
Lets say IF the hotel you are at let each device use the internet for a limited amount of time, they must have a way of identifying each device. And a router tells devices apart is by their MAC addresses. Fortunately for us, we can change our MAC address easily.