A Media Access Control (MAC) address is a hardware identifier used for a…
2023
A Media Access Control (MAC) address is a hardware identifier used for a network interface at the data-link layer and is usually made up of ______ bits.
Answer: C. 48 — CONCEPT:The width of a binary identifier is measured in bits. If an identifier contains n bits, it can represent 2ⁿ distinct bit patterns. Network standards…
- A.
16
- B.
32
- C.
48
- D.
128
Show answer & explanation
Correct answer: C
CONCEPT:
The width of a binary identifier is measured in bits. If an identifier contains n bits, it can represent 2ⁿ distinct bit patterns. Network standards fix the width so devices interpret the identifier consistently.
APPLICATION:
A standard MAC-48 address contains 6 octets.
Each octet contains 8 bits, so the total width is 6 × 8 = 48 bits.
CONTRAST:
A 16-bit field contains only 2¹⁶ patterns and is much shorter than a standard MAC-48 identifier.
A 32-bit field contains 2³² patterns; 32 bits is also the familiar width of an IPv4 address, not a standard MAC-48 identifier.
A 128-bit field contains 2¹²⁸ patterns; 128 bits is the familiar width of an IPv6 address, not a standard MAC-48 identifier.
CROSS-CHECK:
A MAC-48 address is conventionally written as 12 hexadecimal digits. Each hexadecimal digit represents 4 bits, and 12 × 4 again gives 48 bits.
RESULT:
Therefore, the usual MAC address width asked for here is 48 bits.