Physical address assigned to a NIC card, which uniquely identifies each device on a given network.
<aside> 💡 First three pair of MAC address are identifiers. 00:0c:29:0a:42:05 → VMware, Inc.
</aside>
IG bit distinguishes whether the MAC address is an individual(0) or group(1) address.
*06-00-00-00-00-00 > Hexa to Binary >* 0000011**0** 00000000 00000000 00000000 00000000 00000000
When the least significant bit is 0 (zero), the frame is meant to reach only one receiving NIC and is a unicast address If the least significant bit of the first octet is set to 1 (i.e. the second hexadecimal digit is odd) the frame will still be sent only once; however, NICs will choose to accept it based on criteria other than the matching of a MAC address: for example, based on a configurable list of accepted multicast MAC addresses. This is called multicast addressing.
U/L bit indicates whether the MAC address has been universally(0) or locally assigned(1). The Universally Administered or Locally Administered address bit is used to tell if the MAC address is the burned-in-address(BIA) or a MAC address that has been changed locally. Maybe this bit served a purpose in the past but with modern applications on Windows or *nix systems you can change the MAC address to almost anything and this bit does not have to be set to tell the system that you are no longer using the manufacturer’s BIA.
06-00-00-00-00-00 > Hexa to Binary > 000001**1**0 00000000 00000000 00000000 00000000 00000000
If the bit is set to 0 then the MAC address is recognized as a BIA MAC address. When the bit is set to 1 then the MAC address is recognized as being changed from the BIA to a unique MAC address that is locally setup.