0. 实验文件地址

http://www-net.cs.umass.edu/wireshark-labs/Wireshark_TCP_v7.0.pdf

wireshark如何显示序列号 wireshark包序号_IP

序号(seq):用来标识从TCP发送端向TCP接收端发送的数据字节流。 它表示在这个报文段中的第一个数据字节。

举个例子:以下是一个文件被分成几个报文段

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第一个报文段的序号为 0 , 第二个报文段的序号为 1000 。

确认序号(seq + 1):包含发送确认的一端所期望收到的下一个序号。因此,确认序号应该是 上次已成功收到的数据字节序号加1。还是看上图例子,假如接收端已经收到了第一个报文段(序号为0~999),那么它期望下一次接收的序号应该为1000,则该接收端的确认序号为1000。

下面是标志位对应的功能:

  1. URG:紧急指针有效。
  2. ACK:确认序号有效。
  3. PSH:接收方应尽快将这个报文段交给应用层。
  4. RST:重新连接。
  5. SYN:同步序号用来发起一个连接。
  6. FIN:发送端完成任务。

套接字 :

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SYN = 1表示正在建立连接,SYN = 0表示连接已建立。

client_isn和server_isn都是随机生成的,目的就是为了防止被恶意攻击。

1. Capturing a bulk TCP transfer from your computer to a remote server

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Packets Display

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2. A first look at the captured trace

Question & Answer

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  1. The IP address of the client computer is 192.168.1.102. The TCP port number is 1161.
  2. The IP address is 128.119.245.152. The TCP port number is 80.
  3. Sorry, I don’t create my own trace.

3. TCP Basics

Question & Answer

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  1. The sequence number of the TCP SYN segment is 0. Flags in the segment that identifies the segment as a SYN segment.

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5. The sequence number of the SYNACK segment is 0. The value of the Acknowledgement field in the SYNACK segment is 1. Flags identifies the segment as a SYNACK segment.

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  1. The sequence number of the TCP segment containing the HTTP POST command is 1.

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7. The sequence numbers of the first six segments in the TCP connection are 1, 566, 2026, 3486, 4946, 6406.

8. The length of the first segment is 565, others are 1460.

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  1. 5840.No throttle is made due to the lack of buffer space.
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  3. There is no retransmmited segment in the trace file.
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  5. 164090 bytes.
  6. 164090 / 5.297341 = 30975.92

4. TCP congestion control in action

Question & Answer

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13. To be continue

14. To be continue