Wireshark Lab: UDP v7.0

0. 实验文件地址

http://www-net.cs.umass.edu/wireshark-labs/Wireshark_UDP_v7.0.pdf


为什么UDP提供了检验和 ：不能保证源和目的之间的所有链路都提供差错检测（端到端原则）。

1. The Assignment

I downloaded the zip.

1.1 Packets Display

1.2 Question & Answer

1. 
2. From above picture, we can see the length of UDP is 58 bytes, the length of the UDP payload is 50 bytes, so the length of each of the UDP header fields is 58 - 50 = 8 bytes. You can verify the packet which length is 93 bytes.
3. The length indicates the number of bytes in the UDP segment(header plus data).
4. 50 bytes.
5. 
   From above picture, we can see source port number is 4334, the hexadecimal is 10ee. So when the hexadecimal is ffff, the largest source possible port number is 65535.
6. 
   The hexadecimal is 11, the decimal is 17.
7.