To obtain the MAC Address from a Nintendo DS, you must first insert a Nintendo Wi-Fi Connection compatible game and access the WFC Setup Utility.
Please note that the exact steps to access the setup utility varies by game. However, the setup utility is a standard menu, included with all WFC-compatible games.
After accessing the utility, tap “Options,” then “System Information.”
The MAC Address and Nintendo WFC ID will be listed on the screen.
Unless the game player has successfully connected with Nintendo Wi-Fi Connection, the WFC ID will be blank.