TLD/coについて、ここに記述してください。
$ dnsq ns co a.root-servers.net
2 co: 398 bytes, 1+0+6+12 records, response, noerror query: 2 co authority: co 172800 NS ns1.cctld.co authority: co 172800 NS ns2.cctld.co authority: co 172800 NS ns3.cctld.co authority: co 172800 NS ns4.cctld.co authority: co 172800 NS ns5.cctld.co authority: co 172800 NS ns6.cctld.co additional: ns1.cctld.co 172800 A 156.154.100.25 additional: ns2.cctld.co 172800 A 156.154.101.25 additional: ns3.cctld.co 172800 A 156.154.102.25 additional: ns4.cctld.co 172800 A 156.154.103.25 additional: ns5.cctld.co 172800 A 156.154.104.25 additional: ns6.cctld.co 172800 A 156.154.105.25 additional: ns1.cctld.co 172800 AAAA 2001:502:2eda::21 additional: ns2.cctld.co 172800 AAAA 2001:502:ad09::21 additional: ns3.cctld.co 172800 AAAA 2610:a1:1009::21 additional: ns4.cctld.co 172800 AAAA 2610:a1:1010::21 additional: ns5.cctld.co 172800 AAAA 2610:a1:1011::21 additional: ns6.cctld.co 172800 AAAA 2610:a1:1012::21
$ dnsq ns co 156.154.100.25
2 co: 398 bytes, 1+6+0+12 records, response, authoritative, noerror query: 2 co answer: co 900 NS ns5.cctld.co answer: co 900 NS ns4.cctld.co answer: co 900 NS ns2.cctld.co answer: co 900 NS ns6.cctld.co answer: co 900 NS ns1.cctld.co answer: co 900 NS ns3.cctld.co additional: ns1.cctld.co 7200 A 156.154.100.25 additional: ns1.cctld.co 7200 AAAA 2001:502:2eda::21 additional: ns2.cctld.co 7200 A 156.154.101.25 additional: ns2.cctld.co 7200 AAAA 2001:502:ad09::21 additional: ns3.cctld.co 7200 A 156.154.102.25 additional: ns3.cctld.co 7200 AAAA 2610:a1:1009::21 additional: ns4.cctld.co 7200 A 156.154.103.25 additional: ns4.cctld.co 7200 AAAA 2610:a1:1010::21 additional: ns5.cctld.co 7200 A 156.154.104.25 additional: ns5.cctld.co 7200 AAAA 2610:a1:1011::21 additional: ns6.cctld.co 7200 A 156.154.105.25 additional: ns6.cctld.co 7200 AAAA 2610:a1:1012::21
$ dnsq ns cctld.co 156.154.100.25
2 cctld.co: 88 bytes, 1+0+1+0 records, response, authoritative, noerror query: 2 cctld.co authority: co 900 SOA ns1.cctld.co hostmaster.neustar.biz 2017271409 900 900 604800 86400
$ dnsq a zzz.cctld.co 156.154.100.25
1 zzz.cctld.co: 92 bytes, 1+0+1+0 records, response, authoritative, nxdomain query: 1 zzz.cctld.co authority: co 900 SOA ns1.cctld.co hostmaster.neustar.biz 2017271409 900 900 604800 86400