Which part of the 48-bit, 12-digit hexadecimal number known as the
Media Access Control (MAC) address identifies the manufacturer of the
network device?

A.
The last three bytes

B.
The first two bytes

C.
The first three bytes

D.
The second half of the MAC address

Explanation:
The first three bytes (or first half) of the six-byte MAC address is the manufacturer’s identifier (see
Table). This can be a good troubleshooting aid if a network device is acting up, as it will isolate the
brand of the failing device. The other answers are distracters. Source:
Mastering Network Security by Chris Brenton (Sybex, 1999).