Ethernet Fields
| Field | Bytes | Description |
|---|---|---|
| Preamble | 7 | 56 alternating ones and zeros used for synchronization ( 101010…) |
| SFD | 1 | Start Frame Delimiter - designates the end of the preamble (10101011) |
| Destination MAC Address | 6 | Ethernet MAC address of the destination device |
| Source MAC Address | 6 | Ethernet MAC address of the source device |
| EtherType | 2 | Describes the data contained the payload |
| Payload | 46-1500 | Layer 3 and higher data |
| FCS | 4 | Frame check Sequence - CRC checksum of the frame |
MAC Address
Ethernet Media Access Control address.
- The physical address of a network adapter.
- Unique to device.
- 48bits/ 6bytes long.
- Displayed in hexadecimal
CSMA/CD
载波侦听/冲突检测，用于半双工路线上通信的一种通信协议。