实验6利用WireShark分析IP协议1.doc

计算机网络实验报告
年级: 姓名: 学号:
实验日期:
实验名称: 利用WireShark分析IP协议
实验目的
利用wireshark分析ip协议,学****了解ip数据包。
学****ip报文段的各领域。
实验器材
的计算机主机;
抓包工具wireshark和截图工具snagit。
三、实验内容
1. Select the first ICMP Echo Request message sent by puter, and expand
the Protocol part of the packet in the packet details window. What is the IP address of puter?
实验结果如下:
2. Within the IP packet header, what is the value in the upper layer protocol field?
答:the upper layer protocol field is 1
实验结果如下:
3. How many bytes are in the IP header? How many bytes are in the payload of the
IP datagram? Explain how you determined the number of payload bytes.
答:56-20=36就是有效载荷的长度,即此IP数据报的有效载荷为36字节
实验结果如下:
4. Has this IP datagram been fragmented? Explain how you determined whether or
not the datagram has been fragmented.
答:没有分片,原因:flag 和 offset都为0;
实验结果如下如:
5. Which fields in the IP datagram always change from one datagram to the next
within this series of ICMP messages sent by puter?
答:分析结果之TTL,首部检验和,标识等一直在不断地变化。
6. Which fields stay constant? Which of the fields must stay constant? Which fields
must change? Why?
答:分析可知:
stay constant:版本号首部长度,服务类型,标志,偏移,上层协议,目的和源IP地址
must stay constant:必须保持不变的是:版本号源和目的IP地址
must change:标识,首部检验和
7. Describe the pattern you see in the values in the Identification field of the IP
Datagram
答:the pattern is:每一个IP数据报头部的标识号域都不一样,每次加一
8. What is the value in the Identification f