MAC (Media Access Control) address filtering is a security measure that is used to allow or block access to a network based on the MAC address of a device. Every device that is connected to a network has a unique MAC address, which is a series of numbers and letters that identifies the device.
MAC address filtering works by creating a list of allowed or blocked MAC addresses. When a device tries to access the network, the network checks its MAC address against the list. If the MAC address is on the allowed list, the device is granted access to the network. If the MAC address is on the blocked list, the device is denied access to the network.
MAC address filtering can be used to secure a network by limiting access to only devices that have been authorized to access the network. However, it should be used in conjunction with other security measures, as it is relatively easy to spoof a MAC address and gain unauthorized access to a network.