The least significant bit of the first octet of a MAC
address determines if the address is an individual/unicast (0 ) or
group/multicast (1 ) address. Multicast addresses are used to group logically
related stations. The broadcast address (destination address field is all 1s)
is a multicast address that addresses all stations on the Local Area Network (LAN). The
Ethernet MAC supports the transmission and reception of unicast, multicast, and broadcast
packets.
The address is transmitted in an Ethernet frame’s least significant bit first. So, the bit representing an individual or group address is the first bit to appear in an address field of the Ethernet frame.