6.033 Lecture 14 The “dig” Commandgraphics8.nytimes.com from T-Mobile Cell Phonegraphics8.nytimes.com from T-Mobile Cell PhoneMIT OpenCourseWarehttp://ocw.mit.edu 6.033 Computer System Engineering Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.6.033 Lecture 14DNS and Content Delivery NetworksSam MaddenKey ideas:Domain name serviceContent delivery networksNetwork overlaysThe “dig” Command;; QUESTION SECTION:;csail.mit.edu. IN A;; ANSWER SECTION:csail.mit.edu. 5921 IN A 128.30.2.121;; AUTHORITY SECTION:csail.mit.edu. 15152 IN NS AUTH-NS0.csail.mit.edu.csail.mit.edu. 15152 IN NS AUTH-NS1.csail.mit.edu.csail.mit.edu. 15152 IN NS AUTH-NS2.csail.mit.edu.csail.mit.edu. 15152 IN NS AUTH-NS3.csail.mit.edu.The question we askedThe answerServersthatcan answerthequestiondig csail.mit.edu“Time to Live” (TTL)Type of recordA = “Address”NS = “Name server”graphics8.nytimes.com from T-Mobile Cell Phone-bash ~ % dig graphics8.nytimes.com; <<>> DiG 9.4.2-P2 <<>> graphics8.nytimes.com;; global options: printcmd;; Got answer:;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27018;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0;; QUESTION SECTION:;graphics8.nytimes.com. IN A;; ANSWER SECTION:graphics8.nytimes.com. 281 IN CNAME graphics478.nytimes.com.edgesuite.net.graphics478.nytimes.com.edgesuite.net. 13964 IN CNAME a1116.x.akamai.net.a1116.x.akamai.net. 5 IN A 8.17.64.78a1116.x.akamai.net. 5 IN A 8.17.64.24graphics8.nytimes.com from T-Mobile Cell Phone-bash ~ % traceroute 8.17.64.78traceroute to 8.17.64.78 (8.17.64.78), 64 hops max, 40 byte packets1 158.15.184.10.in-addr.arpa (10.184.15.158) 2325.487 ms * *2 * * 178.15.184.10.in-addr.arpa (10.184.15.178) 3768.802 ms3 226.1.184.10.in-addr.arpa (10.184.1.226) 2230.431 ms 1706.115 ms 4265.992 ms4 33.96.184.10.in-addr.arpa (10.184.96.33) 3022.872 ms 2085.019 ms 1003.134 ms5 m8e065e42.tmodns.net (66.94.6.142) 494.165 ms 1096.573 ms 1043.394 ms6 209.96.184.10.in-addr.arpa (10.184.96.209) 544.710 ms 300.269 ms 520.475 ms7 220.96.184.10.in-addr.arpa (10.184.96.220) 460.470 ms 916.142 ms 523.900 ms8 * * *9 ge-6-20.car1.Atlanta1.Level3.net (4.79.213.49) 2439.082 ms 2411.253 ms 2501.724 ms10 ae-27-52.car1.Atlanta4.Level3.net (4.68.103.44) 2039.606 ms 3383.729 ms 3697.863 ms11 8.17.64.78 (8.17.64.78) 3862.096 ms 2918.443 ms 600.868 msdig google.comANSWER SECTION:google.com. 282 IN A 209.85.171.100google.com. 282 IN A 74.125.45.100google.com. 282 IN A
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