MAC filtering

A MAC filter is a network access control, which allows only devices with certain MAC address to access the network. Typically, a MAC filter is applied in a LAN or WAN and stored in a table in the router ( firewall). A MAC filter applies a variety of reasons as a safety weak access control.

MAC spoofing

The MAC address is not an immutable property of the respective network node, because the MAC address is not transmitted by the network adapter (hardware ) itself to the router, but read by the operating system or the network manager (software) first from the adapter and then transmitted. The read address can be easily changed by appropriate software and therefore provides no way to secure identification of a network device. Thus, if the address of a participating node is known, an attacker can change the address of his computer suitable so as to sneak a new user account. Furthermore, the eavesdropping of wireless traffic, the MAC address is the first feature that is known to the intruder. The MAC address can not be unique, as there are network protocols that change the MAC address of the network card and then address the computer via this address. So a MAC filter provides only a very weak protection of a network.