Ethernet Packet

7 Main Parts of Ethernet Packet:

  • Preamble
    Seven bytes of useful information. One portion, for example, is the first bit that determines whether the packet should be multi-cast, sent to multiple devices, or sent to just the destination device.
  • Start-of-Frame Delimiter
    A series of 8 bits that tells the receiver the real message is starting. In other words, it’s a way for the two devices to synchronize, much like two spies synchronize their watches to ensure they’re on the same time frame.
  • Destination Address
    Where the packet is going.
  • Source Address
    Where the packet came from.
  • Length
    The full size of the packet. Ensures the destination device “listens” for the full message.
  • Data
    The actual data being sent, as well as information for other, higher protocols.
  • Frame Check Sequence
    A calculated number the destination device uses to ensure it received all the data.

« Back Next »