What is the fixed header length of an Ethernet frame?

What is the fixed header length of an Ethernet frame?

• A. 14-byte
• B. 12-byte
• C. 16-byte
• D. 8-byte

Answer: (A)

Ethernet frames have a fixed header length of 14 bytes. This header is made up of the destination MAC address (6 bytes), the source MAC address (6 bytes), and the EtherType/length field (2 bytes). The preamble and start-of-frame delimiter belong to the physical layer and are not part of the frame header, while the 4-byte Frame Check Sequence is a trailer, not the header. The payload size can vary, but the header length stays constant at 14 bytes.

Ethernet frames have a fixed header length of 14 bytes. This header is made up of the destination MAC address (6 bytes), the source MAC address (6 bytes), and the EtherType/length field (2 bytes). The preamble and start-of-frame delimiter belong to the physical layer and are not part of the frame header, while the 4-byte Frame Check Sequence is a trailer, not the header. The payload size can vary, but the header length stays constant at 14 bytes.