Which statement is true about Ethernet frame sizing?

• A. The maximum Ethernet frame size is 1518 bytes, consisting of a 14-byte header, a 1500-byte payload, and a 4-byte CRC
• B. The maximum Ethernet frame size is 1500 bytes
• C. The minimum Ethernet frame size is 62 bytes
• D. The minimum Ethernet frame size is 66 bytes

Answer: (A)

Ethernet frames have a fixed header, a payload, and a trailer. The header is 14 bytes (destination MAC 6 + source MAC 6 + EtherType/Length 2). The payload can be up to 1500 bytes, and the trailer is a 4-byte FCS (CRC). Add those up and you get 14 + 1500 + 4 = 1518 bytes, which is the maximum size of a standard Ethernet frame.

So the statement that the maximum frame size is 1518 bytes is the correct one because it accounts for the full frame: header, payload, and CRC. The other options mix up parts of the frame—placing only the payload as the maximum, or misstating the minimum size. The true minimum frame size is 64 bytes (14-byte header + 46-byte minimum payload + 4-byte FCS), so 62 or 66 bytes are not accurate. VLAN tagging can increase the maximum slightly to 1522 bytes, but that’s outside the scope of standard Ethernet framing.