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Manually changing MAC addresses

How to do it, if your email adapter is programmable.


Manually changing MAC addresses
Serdar Yegulalp

The MAC address (or Media Access Control) of a network adapter is a hardware-level ID number that uniquely identifies a network card. Some network cards come with a MAC address hard-wired, but some can have their MAC address changed through software. (Check the network card's documentation to see if this is possible.)

If your NIC is one of the latter, then you can use the following procedure to edit the MAC address in Windows 2000.

  1. Open the Network and Dial-Up Connections window, and right-click on the network connection with the adapter you wish to edit. Select Properties.

  2. Click the Configure button to edit the properties of the network adapter.

  3. Select the Advanced tab. Select Locally Administered Address and enter the new MAC value. (If Locally Administered Address does not appear, then chances are your MAC address can't be edited.)

The same change can be made directly to the Registry:

  1. Open REGEDT32 and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

  2. One of the subkeys under Services will be the driver name for your NIC. If you don't know what the driver name is, you can find out by getting the Properties of the NIC as above, clicking on the Driver tab, and then clicking Driver Details. My server has an SMC brand NIC in it, with the driver name SMCPWR2N.SYS. Consequently, the subkey is named SMCPWR2N.

  3. Add a new REG_SZ value in the appropriate subkey, named Old MAC Address. Add the new MAC address to use as the string value for this key.

Either way, when you make the listed changes, you need to reboot the computer. After rebooting, open up a command prompt and type ipconfig /all to verify that the new address has taken effect.

Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter.

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