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2
3
4
5
6
7
8
9

|以太网头部｜IP头部｜TCP头部｜用户数据｜以太网尾部｜


| Version | Header Length | Type of Service | Total Length    |
| Identification          | Flags           | Fragment Offset |
| TTL                     | Protocol        | Header Checksum |
| Source IP Address(4byte)                                    |
| Destination IP Address(4byte)                               |
| Options                                   | Padding         |

1
2

v4
v6

1

20-60

1

0-255

1
2
3

1:ICMP
6:TCP(TELNET)
17:UDP