MAC filters are an age-old technique used for authentication and authorization and have their roots in the wired world. Unfortunately, they fail miserably in the wireless world.

The basic idea is to authenticate based on the MAC address of the client. The MAC filter is an identification code assigned to a network interface; a router will be able to check this code and compare it to a list of approved MACs. This list of allowed MAC addresses will be maintained by the network administrator and will be fed into the access point. We will now take a look at how easy it is to bypass MAC filters.