Briefly discuss the following Ethernet II frame type fields and structures: Preamble, Destination Address Field, Source Address Field, and Type Field.

Question

What will be an ideal response?

Answer 1

Preamble: The preamble is eight bytes long and consists of alternating 1s and 0s. As its name indicates, this special string of bits precedes the actual Ethernet frame itself, and is not counted as part of the overall frame length. The final byte ends in a pattern, the start frame delimiter (SFD), of 10101011, indicating the start of the Destination Address field. This field provides the necessary timing used by the receiver to interpret the 1s and 0s in a frame, and it builds in the time necessary for Ethernet circuitry to recognize and begin to read incoming data.
Destination Address Field: The Destination Address field is six bytes long and indicates the data link address (also referred to as the hardware address or MAC address) of the destination IP host. The destination address may be broadcast, multicast, or unicast. Address Resolution Protocol (ARP) is used to obtain the hardware address of the destination IP host (if the destination is local), or the next-hop router (if the destination is remote).
Source Address Field: The Source Address field is six bytes long and indicates the sender's hardware address. This field can only contain a unicast address - it cannot contain a broadcast or multicast address.
Type Field: Two bytes long and identifies the protocol that is using this frame type.