实验四利用wireshark分析DNS..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DNS　 实验目的 学会使用nslookup工具查询并分析Internet 域名信息或诊断DNS 服务器。学会使用ipconfig工具进行分析。 会用wireshark分析DNS协议。对DNS协议有个全面的学习与了解。 实验器材 接入Internet的计算机主机； 2、抓包工具wireshark和截图工具snagit。 三、实验内容 1. Run nslookup to obtain the IP address of a Web server in Asia. the IP address of ：00 2. Run nslookup to determine the authoritative DNS servers for a university in Europe. 实验结果如下图： 3. Run nslookup so that one of the DNS servers obtained in Question 2 is queried for the mail servers for Yahoo! mail. 实验结果如下图： 4. Locate the DNS query and response messages. Are then sent over UDP or TCP? 答：DNS query and response messages如下图标注， They ate sent over UDP ； 5. What is the destination port for the DNS query message? What is the source port of DNS response message? 答：the destination port is： 64211（64211） the source port is：domain（53） 6. To what IP address is the DNS query message sent? Use ipconfig to determine the IP address of your local DNS server. Are these two IP addresses the same? 答：ip地址99 ，这两个IP地址是一样的。试验截图如下 7. Examine the DNS query message. What “Type” of DNS query is it? Does the query message contain any “answers”? 答：“Type” of DNS query is（host address） 没有包含“answer”； 8. Examine the DNS response message. How many “answers” are provided? What do each of these answers contain? 答：“answers”如下图： 9. Consider the subsequent TCP SYN packet sent by your host. Does the destination IP address of the SYN packet correspond to any of the IP addresses provided in the DNS response message? 答： 10. This web page contains images. Before retrieving each image, does your host issue new DNS queries? 答： my hostissue don’t issue new DNS queries。 11. What is the destination port for the DNS query message? What is the source port of DNS response message? 答：the destination port for the DNS query message： the source port of DNS response message：