Some people think that you cannot change your MAC address (Media Access Control), but it is possible. The physical address cannot be altered. But there are means that allow you to spoof or change the address that an OS (operating system) reports.
Why Make Changes?
One reason why people do this is for privacy. A user might also change it for interoperability while others do it to connect to a Wi-Fi spot. There are also ISPs (Internet service providers) that hold their service to an address. If you are going to install a router or change a network card, the service would not be accessible. Updating the address will remedy the situation.
Another reason is that some application licenses are tied up to particular addresses. Changing the Media Access Control is the only option. In this instance, the address will revert back once you reboot the computer. These addresses are 48 bits long.
Changing the Address on Mac OS X
The modifications on a Mac are similar to the way it is done on Linux. On Macs, the changes have to be performed as superuser. This only functions with the Ethernet card of the computer. Spoofmac can be used to modify the address.
There are two methods you can use:
sudo ifconfig en0 ether 00:01:02:03:04:05
or
sudo ifconfig en0 lladdr 00:01:02:03:04:05
Change Your MAC address in Windows
If you use Windows XP, the method is quite different. You have to go to the Advanced tab at the Ethernet adapter’s Properties menu. From there go to the address. The name may be Mac Address, Network Address, Ethernet Address or Locally Administered Address. The name varies because drivers use different methods for changing the address.
Another Method for Windows XP
If you have Administrative User Rights in Windows XP, you can go to the Windows registry. Go to Start, Run and type “regedit” without the quotes. Click Ok and the Registry Editor will open. Go to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ Class\{4D36E972-E325-11CE-BFC1-08002bE10318}\
Below this key are several sub keys with names like 0002, 00001, 0000 and so forth. You can presume any Media Access Control address by locating a key that manages the NIC you want to modify. You have to put in a “Network Address” string value and set it to the address that you want to modify as a 12 digit hex number (i.e., 000000000001).
To get the key you have to go through them and find the “DriverDesc” value.
Keep looking until you see the one that corresponds with the NiC that you want to change. Once you set “Network Address” on the address, enable or disable to restart the NIC. Use the “ipconfig /all” or “getmac” command to verify the change. This method works for Windows XP, Vista and 2000.
Other Information
A MAC address is a computer’s real name on a local area network (LAN). An Ethernet Media Access Control address is a 6 byte number. These are depicted as the aforementioned 12 digit number. Translation of IPs to these addresses is via the Address Resolution Protocol (ARP).
If your computer has an IP of 192.168.1.1 and it must send data to another computer with a 192.168.1.2 IP, 192.168.1.1 will transmit a broadcast to every LAN station to determine which one has the 192.168.1.2 address. There will be a response with its address. This is subsequently cached for use later.
Because you can change your , it not recommends that you rely on this solely for identification. There are other standards such as IEEE 802.1x available.
