1. ccTLD/tk
https://en.wikipedia.org/wiki/.tk
tk, ns.tk zone が同居 (tk は子ゾーン ns.tk 内の名前を指定している）
%dnsq ns tk a.root-servers.net
2 tk: 263 bytes, 1+0+4+8 records, response, noerror query: 2 tk authority: tk 172800 NS a.ns.tk authority: tk 172800 NS b.ns.tk authority: tk 172800 NS c.ns.tk authority: tk 172800 NS d.ns.tk additional: a.ns.tk 172800 A 194.0.38.1 additional: b.ns.tk 172800 A 194.0.39.1 additional: c.ns.tk 172800 A 194.0.40.1 additional: d.ns.tk 172800 A 194.0.41.1 additional: a.ns.tk 172800 28 \040\001\006x\000P\000\000\000\000\000\000\000\000\000\001 additional: b.ns.tk 172800 28 \040\001\006x\000T\000\000\000\000\000\000\000\000\000\001 additional: c.ns.tk 172800 28 \040\001\006x\000X\000\000\000\000\000\000\000\000\000\001 additional: d.ns.tk 172800 28 \040\001\006x\000\134\000\000\000\000\000\000\000\000\000\001
%dnsq ns tk 194.0.38.1
2 tk: 263 bytes, 1+4+0+8 records, response, authoritative, noerror query: 2 tk answer: tk 86400 NS a.ns.tk answer: tk 86400 NS b.ns.tk answer: tk 86400 NS c.ns.tk answer: tk 86400 NS d.ns.tk additional: a.ns.tk 10800 A 194.0.38.1 additional: b.ns.tk 10800 A 194.0.39.1 additional: c.ns.tk 10800 A 194.0.40.1 additional: d.ns.tk 10800 A 194.0.41.1 additional: a.ns.tk 10800 28 \040\001\006x\000P\000\000\000\000\000\000\000\000\000\001 additional: b.ns.tk 10800 28 \040\001\006x\000T\000\000\000\000\000\000\000\000\000\001 additional: c.ns.tk 10800 28 \040\001\006x\000X\000\000\000\000\000\000\000\000\000\001 additional: d.ns.tk 10800 28 \040\001\006x\000\134\000\000\000\000\000\000\000\000\000\001
%dnsq ns ns.tk 194.0.38.1
2 ns.tk: 263 bytes, 1+4+0+8 records, response, authoritative, noerror query: 2 ns.tk answer: ns.tk 14400 NS a.ns.tk answer: ns.tk 14400 NS b.ns.tk answer: ns.tk 14400 NS c.ns.tk answer: ns.tk 14400 NS d.ns.tk additional: a.ns.tk 14400 A 194.0.38.1 additional: b.ns.tk 14400 A 194.0.39.1 additional: c.ns.tk 14400 A 194.0.40.1 additional: d.ns.tk 14400 A 194.0.41.1 additional: a.ns.tk 14400 28 \040\001\006x\000P\000\000\000\000\000\000\000\000\000\001 additional: b.ns.tk 14400 28 \040\001\006x\000T\000\000\000\000\000\000\000\000\000\001 additional: c.ns.tk 14400 28 \040\001\006x\000X\000\000\000\000\000\000\000\000\000\001 additional: d.ns.tk 14400 28 \040\001\006x\000\134\000\000\000\000\000\000\000\000\000\001