User's Manual

based on a 64(40)-bit shared key algorithm.
6. What is a MAC Address?
The Media Access Control (MAC) address is a unique number assigned
by the manufacturer to any Ethernet networking device, such as a
network adapter, that allows the network to identify it at the hardware
level. For all practical purposes, this number is usually permanent.
Unlike IP addresses which can change every time a computer logs on to
the network, the MAC address of a device stays the same, making it a
valuable identifier for the network.