Appendix A. MAC Address Filtering

Just like a wired NIC, a wireless NIC also has a MAC address, which is a unique identification for every single NIC manufactured, much like a social security number or a set of fingerprints. It is possible to use MAC addresses as a security measure for your wireless network.

Because you know the MAC address for each wireless NIC you have purchased and planned to use on your network, it is possible to “lock” those into your wireless router and instruct it to let only those wireless NICs access your network. Then, if someone should try to access the wireless network using a laptop with a different NIC (that is, a different MAC address), the wireless router will deny access, even if the correct SSID and encryption key are provided.