TLD/fr/NXDOMAINについて、ここに記述してください。

$ dnsq ns fr 193.176.144.22

2 fr:
108 bytes, 1+5+0+0 records, response, authoritative, noerror
query: 2 fr
answer: fr 172800 NS g.ext.nic.fr
answer: fr 172800 NS d.nic.fr
answer: fr 172800 NS d.ext.nic.fr
answer: fr 172800 NS f.ext.nic.fr
answer: fr 172800 NS e.ext.nic.fr

$ dnsq a zzz.g.ext.nic.fr 193.176.144.22

1 zzz.g.ext.nic.fr:
378 bytes, 1+0+6+11 records, response, noerror
query: 1 zzz.g.ext.nic.fr
authority: nic.fr 172800 NS ns1.ext.nic.fr
authority: nic.fr 172800 NS ns4.ext.nic.fr
authority: nic.fr 172800 NS ns3.nic.fr
authority: nic.fr 172800 NS ns2.nic.fr
authority: nic.fr 172800 NS ns1.nic.fr
authority: nic.fr 172800 NS ns6.ext.nic.fr
additional: ns1.ext.nic.fr 172800 A 193.51.208.13
additional: ns1.nic.fr 172800 A 192.134.4.1
additional: ns1.nic.fr 172800 28 \040\001\006|"\030\000\002\000\000\000\000\000\004\000\001
additional: ns2.nic.fr 172800 A 192.93.0.4
additional: ns2.nic.fr 172800 28 \040\001\006`0\005\000\001\000\000\000\000\000\001\000\002
additional: ns3.nic.fr 172800 A 192.134.0.49
additional: ns3.nic.fr 172800 28 \040\001\006`0\006\000\001\000\000\000\000\000\001\000\001
additional: ns4.ext.nic.fr 172800 A 193.0.9.4
additional: ns4.ext.nic.fr 172800 28 \040\001\006|\000\340\000\000\000\000\000\000\000\000\000\004
additional: ns6.ext.nic.fr 172800 A 130.59.31.29
additional: ns6.ext.nic.fr 172800 28 \040\001\006\040\000\000\000\377\000\000\000\000\000\000\000/

この返答からnic.frゾーンが存在していることが分かる。（frと同居ではない! いつからだろう）

nic.frに問い合わせなおし。

$ dnsq a zzz.g.ext.nic.fr 192.134.4.1

1 zzz.g.ext.nic.fr:
91 bytes, 1+0+1+0 records, response, authoritative, nxdomain
query: 1 zzz.g.ext.nic.fr
authority: nic.fr 5400 SOA dnsmaster.nic.fr hostmaster.nic.fr 2016031200 7200 1800 2419200 5400

ext.nic.frゾーンがないことは推測できるが、確認してみる。

$ dnsq ns ext.nic.fr 192.134.4.1

2 ext.nic.fr:
85 bytes, 1+0+1+0 records, response, authoritative, noerror
query: 2 ext.nic.fr
authority: nic.fr 5400 SOA dnsmaster.nic.fr hostmaster.nic.fr 2016031200 7200 1800 2419200 5400