計算機網(wǎng)絡(luò)課程設(shè)計指導(dǎo)書

1、PAGE 陜西師范大學(xué)計算機網(wǎng)絡(luò)實驗報告實驗四 DNS一、實驗?zāi)康?1.熟悉并掌握 wireshark的操作。 2分析DNS協(xié)議。二、實驗器材 1.PC機電腦一臺。 2下載wireshark軟件并安裝三、實驗內(nèi)容及問題回答 1.練習(xí)使用nslookup程序發(fā)送DNS查詢1. Run nslookup to obtain the IP address of a Web server in Asia.德國德累斯頓工業(yè)大學(xué)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.練習(xí)使用ipconfig （1）ipconfig/all（2）.Ipconfig/displaydns（3）.ipconfig/flushdns清除緩存3. Tracing DNS with Wireshark實驗1過程：使用ipconfig清空DNS緩沖存儲；清空瀏覽器的緩存；啟動Wireshark，在filter中輸入“ip.addr=6”;開始抓包；訪問 HYPER

3、LINK ；頁面打開后，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:() 與用本地DNS服務(wù)器的IP地址相同。7. Examine the DNS query message. What “Type” of DNS query is it? Does the沒有應(yīng)答query message contain any “answers”?類型type A答：TYPE為A,沒有應(yīng)

5、答，8. Examine the DNS response message. How many “answers” are provided? What1個應(yīng)答does each of these answers contain?應(yīng)答包含的內(nèi)容答：有一個應(yīng)答。應(yīng)答的內(nèi)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：沒有。實驗2過程：開始抓包；使用nslookup獲取 HYPERLINK 的地址。停止抓包。實驗結(jié)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服務(wù)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”?類型typeA沒有應(yīng)答答：類型為A；沒有應(yīng)答。14. Examine the DNS response message. How many “answers” are provided? Whatdoes each of these answers contain?應(yīng)答包含的內(nèi)容一個應(yīng)答答：有一個應(yīng)答。應(yīng)答的內(nèi)容包括：Name、Type、Class、Time to live、Data、Addr.實驗3. 重復(fù)實驗2的操作，使用nslookup時限定Type為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服務(wù)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：；沒有應(yīng)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個name servers,沒有提供IP地址。實驗4. 重復(fù)實驗3的操作，但是在命令行輸入 Nslookup HYPERLINK http:/www.aiit.or.krwww.aiit.or.kr 實驗結(jié)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服務(wù)器IP地址 答：。不是。與指定的服務(wù)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”?類型為A沒有應(yīng)答22.