your router's mac address is a 12-digit code assigned to a unique piece of hardware for identification, like a social security number. some isps require that you register the mac address of your network card/adapter, which was connected to your cable or dsl modem during installation. if your isps require mac address registration, find your adapter's mac address by doing the following:

    1. click the start button, and select run. run winipcfg, and then click more info. or at the command prompt, run ipconfig/all, and look at your adapter's physical address.

    2. enter those 12 digits into the fields shown in figure 5-25, and click the apply button and continue button. this "clones" your network adapter's mac address onto your router, and prevents you from having to call your isp to change the registered mac address to the router's mac address.