Describe one weakness of MAC address filtering.

What will be an ideal response?

Managing the number of MAC addresses in a medium to large sized wireless network can pose significant challenges. As new users are added to the network and old users leave, MAC address filtering demands constant attention.
MAC addresses are initially exchanged in cleartext. This means that an attacker can easily see the MAC address of an approved device and use it to join the network.
A MAC address can be "spoofed" or substituted.