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数据链路层

Ethernet II / IEEE 802.3
14 字节

目的MAC地址	源MAC地址	类型 (IPv?/ARP)
6 字节	6 字节	2 字节

最小帧：64
最大帧：1518 (14 字节 Mac + 1500 上层数据 + 4 字节 CRC)
帧前导：8 字节 (7 字节前同步码 + 1 字节帧开始定界符)

网络层

20 字节

版本	首部长度	总长度(包括IP头)	Identification（标识）	Flags	片偏移	TTL	协议	头部校验和	源IP地址	目的IP地址
0.5字节	0.5字节	2字节	2 字节	3 bits	13 bits	1 字节	1 字节	2 字节	4 字节	4 字节

Frame 15: 194 bytes on wire (1552 bits), 194 bytes captured (1552 bits) on interface loopback0, id 0
Ethernet II, Src: Microsoft_af:2c:72 (00:15:5d:af:2c:72), Dst: CIMSYS_33:44:55 (00:11:22:33:44:55)
    Destination: CIMSYS_33:44:55 (00:11:22:33:44:55)
        Address: CIMSYS_33:44:55 (00:11:22:33:44:55)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
    Source: Microsoft_af:2c:72 (00:15:5d:af:2c:72)
        Address: Microsoft_af:2c:72 (00:15:5d:af:2c:72)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
    Type: IPv4 (0x0800)
Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1
    0100 .... = Version: 4
    .... 0101 = Header Length: 20 bytes (5)
    Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT)
    Total Length: 180
    Identification: 0xc2eb (49899)
    010. .... = Flags: 0x2, Don't fragment
    ...0 0000 0000 0000 = Fragment Offset: 0
    Time to Live: 64
    Protocol: TCP (6)
    Header Checksum: 0x7956 [validation disabled]
    [Header checksum status: Unverified]
    Source Address: 127.0.0.1
    Destination Address: 127.0.0.1
Transmission Control Protocol, Src Port: 45544, Dst Port: 8888, Seq: 1, Ack: 382, Len: 128
    Source Port: 45544
    Destination Port: 8888
    [Stream index: 0]
    [Conversation completeness: Complete, WITH_DATA (31)]
    [TCP Segment Len: 128]
    Sequence Number: 1    (relative sequence number)
    Sequence Number (raw): 1384029365
    [Next Sequence Number: 129    (relative sequence number)]
    Acknowledgment Number: 382    (relative ack number)
    Acknowledgment number (raw): 1017834986
    1000 .... = Header Length: 32 bytes (8)
    Flags: 0x018 (PSH, ACK)
    Window: 501
    [Calculated window size: 64128]
    [Window size scaling factor: 128]
    Checksum: 0xfea8 [unverified]
    [Checksum Status: Unverified]
    Urgent Pointer: 0
    Options: (12 bytes), No-Operation (NOP), No-Operation (NOP), Timestamps
    [Timestamps]
    [SEQ/ACK analysis]
    TCP payload (128 bytes)
Data (128 bytes)
    Data [truncated]: 0000007c7b2242223a5b332c34312c34332c38362c3138332c3231312c3130342c3132342c36342c38392c3231302c3234352c3231392c3136312c3138312c3233392c3232352c3134352c3134312c31362c32352c3230332c34362c38372c3130372c36392c3232302c32362c313
    [Length: 128]

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