IEEE MAC Address

Section 9.2 of IEEE 802-2001 specification describes the 48-bit universal LAN MAC address, Media Access Control address (Hardware Network Address). The first 24 bits, starting from bit 0 (LSB) to bit 23, is the Organization Unique Identifier (OUI) and is assigned by IEEE if the 2nd LSB (U/L) is set to 0.

• If bit 0 (I/G) is set to 0 then the MAC address is an individual address, identify the destination address as an individual address.
• If bit 0 (I/G) is set to 1 then the MAC address is identify as one or more destination address, broadcast address.
• If bit 1 (2nd bit) is set to 0 then the MAC address is Universally administered address (IEEE).
• If bit 1 (2nd bit) is set to 1 then the MAC address is been locally administered.