2. 實驗五 網路探測實驗 教師： 助教： 1998/10/19 High Speed Network Lab. Department of Computer Information Science, NCTU

3. Outline Requirement Routing Path Measurement Loose SouRce Route Experiment Steps LAN monitoring Network Traffic Statistical Data

4. Surveying Tools (I)

5. Surveying Tools (II)

6. Surveying Tools (III)

7. Requirement Route path measurement Suggested software tool: LAN monitoring Suggested software tool: http://atm5.cis.nctu.edu.tw/~ydlin/course/cn/exp/netprob/index.htm Experiment specification

8. Routing Path Measurement lDNS address translation host name/URL ==> IP address lTTL mechanism IP packet TTL (Time To Live)

9. TTL Mechanism TTL=2 TTL=1 TTL=0 ICMP Router A (Local) B (Remote)

10. Loose SouRce Route (I) Remote Trace Route A (Local) B (Remote) C Router LSRR

11. Loose SouRce Route (II) Round Trip Trace Route A,B (Local) C (Remote) LSRR Router

12. Loose SouRce Route (III) LSRR Supporting Problem A (Local) B (Original Dst) LSRR supporting routers Non-LSRR supporting routers B’ (Replacing Dst) Suggestion: Find a LSRR supporting node nearest from original node

13. Experiment Steps 1. Dst host name 2. LSRR 3. DNS result 4. Visited cache Analysis Table Map

14. LAN Monitoring Starting time Ending time Max byte/sec Average byte/sec Num of packet Num of byte Num of collision

15. Network Traffic Statistical Data Find traffic data in TWNIC web site New Version : http://www.twnic.net/ ‘ 每天 ’ 流量圖 (5 分鐘平均值 ) 最大交大 ==> 高速電腦 28.7 Mb/s (4.6%) 最大高速電腦 ==> 交大 26.9 Mb/s (4.3%) 平均交大 ==> 高速電腦 17.8 Mb/s (2.9%) 平均高速電腦 ==> 交大 15.1 Mb/s (2.4%) 現在交大 ==> 高速電腦 15.8 Mb/s (2.5%) 現在高速電腦 ==> 交大 10.3 Mb/s (1.6%) Old Version : http://www.twnic.net/ver2.html

16. Experiment Records Routing Path Exp. record format LAN monitoring record format Traffic statistical data record format (not necessary)

17. Bonus Trace measurement source code Trace the network in NCTU. Reference: http://www.csie.nctu.edu.tw/~jhliang/netadm1.htm