It is possible to change the MAC (Media Access Control) address that is reported on the operating system, even though most MAC addresses are designed to be permanent. The changing of address is sometimes referred to as “spoofing” and sometimes it becomes necessary to do that in order to maintain privacy, especially when connecting to Wi-Fi hotspots and also to ensure interoperability.

Internet Service Providers (ISPs) usually bind the service to a specific MAC address and this therefore means that once the user changes a network card or a router, he will no longer access the service. One can solve the problem by changing the MAC address of the new interface. In almost the same way, some software licenses are linked to certain MAC addresses.

Since MAC addresses can be changed, it thus would be ill advised to rely on it as a single method of identification. Instead, use another method, such as the IEEE 802.1x which is emerging as a standard authentication method for low-level devices.
Changing MAC in Windows

Here, one can change the MAC address in the Ethernet adapter’s property menu. The exact name on the advanced tab varies according to the Ethernet driver used. Thus, you might find on the “Advanced” tab names such as “Ethernet Address”, “MAC Address”, “Locally Administered Address” or “Network Address”.

A better method but one that requires registry editing permissions would be to pass over the system registry keys that are under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}. The network interfaces are found here and the contents of “NetworkAddress” will be used to set the MAC address of the adapter.

Resetting the adapter can be done using a command line utility called Devcon which Microsoft offers for free. SMAC MAC address Changer is an excellent tool for changing the address for all cards even for those that are not altered through the adapters’ property menu. If you want to check the new MAC address, go to the “Start” button and click on “Run”. On the “Run” line, enter the command module (cmd) and then type “ipconfig /all” into the command prompt. The number that you will see under the physical address is your new MAC address.
Changing the MAC address in a Router

Not all routers have the wherewithal to change the MAC address and for those that do, the changing of the MAC address varies widely. A feature that is present in a router for changing the MAC address is called “clone MAC address”. This will acquire the MAC address of one of the machines in the network and will replace the existing MAC address of the router with the acquired one. Some routers support the option of manually altering the MAC address.
Changing the MAC address in Linux

You can change the MAC address using GNU MAC changer or by entering the following command ‘ifconfig hw