File:MACaddressV3.png

Summary
MAC address format This diagram is intended to capture the rather obtuse terminology associated with byte positioning and the least significant bits of an address associated with multicast and unicast addressing. It is quite common for people to make up MAC addresses without being aware of the implications of such an action; it is equally common for people to appropriate the multicast bit to the wrong position or byte.

Note: This is version 3 of this diagram. The width of it has been reduced to accommodate the MAC address Wiki entry.