ICMP(wireshark实验)

一、实验目的1 了解ICMP协议下数据包相关格式和内容。2 了解ping和tracert两种指令功能。二、实验结果1. What is the IP address of your host? What is the IP address of the destination host?答：IP：192.168.1.101Destination IP：143.89.14.342. Why is it that an ICMP packet does not have source and destination port numbers?答：因为ICMP数据包在网络层封装在IP数据包中，因此不需要destination和source。3. Examine one of the ping request packets sent by your host. What are the ICMP type and code numbers? What other fields does this ICMP packet have? How many bytes are the checksum, sequence number and identifier fields?答：在其他地方没有ICMP数据包因为他没有分组 4. Examine the corresponding ping reply packet. What are the ICMP type and code numbers? What other fields does this ICMP packet have? How many bytes are the checksum, sequence number and identifier fields?答：在其他地方没有ICMP数据包因为他没有分组。5. What is the IP address of your host? What is the IP address of the target destination host?答：IP：192.168.1.101Destination：138.96.146.26. If ICMP sent UDP packets instead (as in Unix/Linux), would the IP protocol number still be 01 for the probe packets? If not, what would it be?答：不是01，因为它的上层协议UDP,所以它的protocolnumber不是ICMP（1）7. Examine the ICMP echo packet in your screenshot. Is this different from the ICMP ping query packets in the first half of this lab? If yes, how so?Ping指令：Tracer指令：答：可以看出两者的checksum、sequence、number、data不同。8. Examine the ICMP error packet in your screenshot. It has more fields than the ICMP echo packet. What is included in those fields?答：可以看出，errorpacket比echopacket多出了Internetprotocol,src:，dst：部分9. Examine the last three ICMP packets received by the source host. How are these packets different from the ICMP error packets? Why are they different?（检查源主机收到的最后三个ICMP数据包。 这些数据包如何与ICMP错误数据包不同？ 他们为什么不同？）10. Within the tracert measurements, is there a link whose delay is significantly longer than others? Refer to the screenshot in Figure 4, is there a link whose delay is significantly longer than others? On the basis of the router names, can you guess the location of the two routers on the end of this link?（在tracert测量中，是否存在延迟比其他延迟更长的链路？