1. watchWWW/upenn.edu
qname minimisationからみのNXDOMAIN返答問題
$ dnsq a www.upenn.edu a.edu-servers.net 1 www.upenn.edu: 326 bytes, 1+0+6+8 records, response, noerror query: 1 www.upenn.edu authority: upenn.edu 172800 NS dns1.udel.edu authority: upenn.edu 172800 NS dns2.udel.edu authority: upenn.edu 172800 NS sns-pb.isc.org authority: upenn.edu 172800 NS adns2.upenn.edu authority: upenn.edu 172800 NS adns1.upenn.edu authority: upenn.edu 172800 NS adns3.upenn.edu additional: dns1.udel.edu 172800 A 128.175.13.16 additional: dns2.udel.edu 172800 A 128.175.13.17
$ dnsq a www.upenn.edu adns2.upenn.edu 1 www.upenn.edu: 77 bytes, 1+1+0+0 records, response, authoritative, noerror query: 1 www.upenn.edu answer: www.upenn.edu 300 CNAME www.upenn.edu-dscg.edgesuite.net
2. CNAME chasing
$ dnsq a www.upenn.edu-dscg.edgesuite.net a.gtld-servers.net 1 www.upenn.edu-dscg.edgesuite.net: 510 bytes, 1+0+13+11 records, response, noerror query: 1 www.upenn.edu-dscg.edgesuite.net authority: edgesuite.net 172800 NS ns1-2.akam.net authority: edgesuite.net 172800 NS usw6.akam.net authority: edgesuite.net 172800 NS adns3.akam.net authority: edgesuite.net 172800 NS ns4-65.akam.net
3. NXDOMAIN 返答
$ dnsq ns edu-dscg.edgesuite.net ns1-2.akam.net 2 edu-dscg.edgesuite.net: 103 bytes, 1+0+1+0 records, response, authoritative, nxdomain query: 2 edu-dscg.edgesuite.net authority: edgesuite.net 180 SOA ns1-2.akamai.com hostmaster.akamai.com 1496149658 900 300 604800 180
$ dnsq ns upenn.edu-dscg.edgesuite.net ns1-2.akam.net 2 upenn.edu-dscg.edgesuite.net: 109 bytes, 1+0+1+0 records, response, authoritative, nxdomain query: 2 upenn.edu-dscg.edgesuite.net authority: edgesuite.net 180 SOA ns1-2.akamai.com hostmaster.akamai.com 1496184102 900 300 604800 180
4. 多段 CNAME
$ dnsq a www.upenn.edu-dscg.edgesuite.net ns1-2.akam.net 1 www.upenn.edu-dscg.edgesuite.net: 82 bytes, 1+1+0+0 records, response, authoritative, noerror query: 1 www.upenn.edu-dscg.edgesuite.net answer: www.upenn.edu-dscg.edgesuite.net 21600 CNAME a1165.dscg.akamai.net