Ethernet Frame Structure

Which field in an Ethernet frame is used primarily for error checking?

How many bytes does the Destination address (DA) field in an Ethernet frame consist of?

If the Data field is less than 46 bytes, what must be done to meet the minimum length requirement?

Which of the following fields is used for synchronization in an Ethernet frame?

What is the primary reason for Ethernet's continued success as a LAN technology?

What is the maximum allowable number of bytes in the Data field of an Ethernet frame?

What does the Frame check sequence (FCS) contain in an Ethernet frame?

Ethernet Frame Structure

Consists of 7 fields: Preamble, Start Frame Delimiter, Destination Address, Source Address, Length/Type, Data, and Frame Check Sequence.

Preamble and Start Frame Delimiter

Preamble consists of 7 bytes, an alternating pattern of ones and zeros.
Start Frame Delimiter consists of 1 byte, an alternating pattern of ones and zeros.
Both are used for synchronization.

Destination and Source Addresses

Destination Address consists of 6 bytes.
Source Address consists of 6 bytes (no specific byte length mentioned).

Length/Type and Data Fields

Length/Type field consists of 2 bytes.
Data field is a sequence of n bytes, where n ≤ 1500.
If Data field length is < 46, it is extended by adding a filler (pad) to bring the length to 46 bytes.

Frame Check Sequence

Consists of 4 bytes.
Contains a 32-bit cyclic redundancy check (CRC) value.
Created by the sending MAC and recalculated by the receiving MAC to check for damaged frames.

Why Ethernet Was Successful

Simpllicity and ease of maintenance contributed to its success.
Ability to incorporate new technologies made it successful.
It is a flexible technology that has evolved to meet media capabilities.
Low cost of installation and upgrade contributed to its success.

This quiz covers the seven fields of an Ethernet frame, including preamble, start frame delimiter, destination address, source address, length/type, and data.