burned in address (BIA)
The Burned-In Address( BIA) is the hardware address or MAC address for a network interface card( NIC), which is normally assigned by the manufacturer and exists only once.
The last six bytes of the MAC address are burned into a ROM on the network card. Hence the designation Burned-In address. In certain cases, the burned-in address can be overwritten by the user. If you change the seventh bit in the first byte of the MAC address, then you can use the U/L bit to change the Organization Unique Identifier( OUI) address assignment to Universal (U) or Local (L).
If the U/L bit is set to 0, it is a Universally Administrated Address( UAA), which is managed by the IEEE. If the U/L bit is set to 1, it is a Locally Administered Address( LAA), which can only be administered locally.