How to Spoof WAN MAC Address in DD-WRT

First, what is a MAC address and why might you want to alter, clone, or spoof it? MAC stands for Media Access Control and it’s a (theoretically) unique 12 hexadecimal digit identifier for a specific piece of network hardware. An example could look like 01-23-45-67-89-AB (remember hexadecimal digits range from 0 to F).

Now why might you want to spoof, clone or alter it? Some examples may include avoiding having to register a new router’s MAC address to an internet service provider, or to obfuscate a network monitor’s ability to tie traffic to a particular piece of hardware, or to circumvent a MAC address blacklist filter preventing a device from connecting.

Here’s how to do it at the router level using DD-WRT, one common free third party router firmware (vendor specific firmware may or may not offer similar functionality):

  1. Enter your router’s IP address in your browser of choice and when prompted, enter your login credentials.
    Note: My router’s IP address is set to 192.168.11.1, yours may be different.

    1_MACClone
  2. Under the “Setup” tab, choose “MAC Address Clone”

    2_MACClone
  3. Click “Enable” and you will be presented with two fields showing the current WAN and Wireless MAC addresses of the router.
    Note: The “Get Current PC MAC Address” button will input the MAC address of the device you are using to access the router. We won’t be using that.

    3_MACClone
  4. For our purposes, I’m only interested in altering the public facing WAN MAC address, so I have altered the last two digits from “B1” to “42” thus making a new address.
  5. Click “Save” and “Apply Settings”
  6. Check the “Status” page and “Router” tab to verify that the change has taken effect.

Congratulations, you’re done! Venture forth and use your newfound powers for good, not evil!