By using the feature of MAC address authentication or MAC address filtering most of the routers enable administrators to block or allow clients on the network. When a computer tries to connect to a network, the router authenticates the device MAC address. It means the router uses the MAC address to identify the computer, if the address is allowed through the filter, the router allows the computer to establish a connection with the network. Staff can also use authentication to protect their network, MAC filtering is especially important if the student or the staff do any banking or access other confidential information from their PC.