计算机网络课程设计指导书

1、PAGE 陕西师范大学计算机网络实验报告实验四 DNS一、实验目的 1.熟悉并掌握 wireshark的操作。 2分析DNS协议。二、实验器材 1.PC机电脑一台。 2下载wireshark软件并安装三、实验内容及问题回答 1.练习使用nslookup程序发送DNS查询1. Run nslookup to obtain the IP address of a Web server in Asia.德国德累斯顿工业大学2. Run nslookup to determine the authoritative DNS servers for a university inEurope.3. Ru

2、n nslookup so that one of the DNS servers obtained in Question 2 is queried forthe mail servers for Yahoo! Mail2.练习使用ipconfig （1）ipconfig/all（2）.Ipconfig/displaydns（3）.ipconfig/flushdns清除缓存3. Tracing DNS with Wireshark实验1过程：使用ipconfig清空DNS缓冲存储；清空浏览器的缓存；启动Wireshark，在filter中输入“ip.addr=6”;开始抓包；访问 HYPER

3、LINK ；页面打开后，停止抓包。4. Locate the DNS query and response messages. Are they sent over UDP or TCP? 答：用的是UDP5. What is the destination port for the DNS query message? What is the source portof DNS response message?答：Src Port :domain(53), Dst Port: domain(53)6. To what IP address is the DNS query message

4、sent? Use ipconfig to determine theIP address of your local DNS server. Are these two IP addresses the same?Ip地址：Ip地址：答：Destination:() 与用本地DNS服务器的IP地址相同。7. Examine the DNS query message. What “Type” of DNS query is it? Does the没有应答query message contain any “answers”?类型type A答：TYPE为A,没有应

5、答，8. Examine the DNS response message. How many “answers” are provided? What1个应答does each of these answers contain?应答包含的内容答：有一个应答。应答的内容包括：Name、Type、Class、Time to live、Data、Addr.9. Consider the subsequent TCP SYN packet sent by your host. Does the destinationIP address of the SYN packet correspond to

6、 any of the IP addresses provided inthe DNS response message?答：不一致10. This web page contains images. Before retrieving each image, does your hostissue new DNS queries?答：没有。实验2过程：开始抓包；使用nslookup获取 HYPERLINK 的地址。停止抓包。实验结果：11. What is the destination port for the DNS query message? What is the source p

7、ortof DNS response message?答：Destination Port：domain(53) Source Port: domain(53)12. To what IP address is the DNS query message sent? Is this the IP address of yourdefault local DNS server? 本地DNS服务器IP地址答：是。13. Examine the DNS query message. What “Type” of DNS query is it? Does thequery message conta

8、in any “answers”?类型typeA没有应答答：类型为A；没有应答。14. Examine the DNS response message. How many “answers” are provided? Whatdoes each of these answers contain?应答包含的内容一个应答答：有一个应答。应答的内容包括：Name、Type、Class、Time to live、Data、Addr.实验3. 重复实验2的操作，使用nslookup时限定Type为NS。16. To what IP address is the DNS query message s

9、ent? Is this the IP address of yourdefault local DNS server?本地DNS服务器IP地址答：相同。17. Examine the DNS query message. What “Type” of DNS query is it? Does thequery message contain any “answers”?答：；没有应答。18. Examine the DNS response message. What MIT name servers does the responsemessage provide? Does this

10、response message also provide the IP addresses of theMIT name servers?答：提供3个name servers,没有提供IP地址。实验4. 重复实验3的操作，但是在命令行输入 Nslookup HYPERLINK http:/www.aiit.or.krwww.aiit.or.kr 实验结果：20. To what IP address is the DNS query message sent? Is this the IP address of yourdefault local DNS server? If not, what does the IP address correspond to?本地DNS服务器IP地址 答：。不是。与指定的服务器的IP地址一致。21. Examine the DNS query message. What “Type” of DNS query is it? Does thequery message contain any “answers”?类型为A没有应答22.