1. watchNS/cz
子ゾーンnic.cz中のENT下の名前をNSに使用している。
$ dnsq ns cz a.root-servers.net
2 cz: 267 bytes, 1+0+4+8 records, response, noerror query: 2 cz authority: cz 172800 NS b.ns.nic.cz authority: cz 172800 NS c.ns.nic.cz authority: cz 172800 NS d.ns.nic.cz authority: cz 172800 NS a.ns.nic.cz additional: b.ns.nic.cz 172800 A 194.0.13.1 additional: b.ns.nic.cz 172800 28 \040\001\006x\000\020\000\000\000\000\000\000\000\000\000\001 additional: c.ns.nic.cz 172800 A 194.0.14.1 additional: c.ns.nic.cz 172800 28 \040\001\006x\000\021\000\000\000\000\000\000\000\000\000\001 additional: d.ns.nic.cz 172800 A 193.29.206.1 additional: d.ns.nic.cz 172800 28 \040\001\006x\000\001\000\000\000\000\000\000\000\000\000\001 additional: a.ns.nic.cz 172800 A 194.0.12.1 additional: a.ns.nic.cz 172800 28 \040\001\006x\000\017\000\000\000\000\000\000\000\000\000\001
1.1. multi-cast
$ dnsq ns cz 194.0.12.1
2 cz: 223 bytes, 1+4+0+6 records, response, authoritative, noerror query: 2 cz answer: cz 18000 NS a.ns.nic.cz answer: cz 18000 NS b.ns.nic.cz answer: cz 18000 NS c.ns.nic.cz answer: cz 18000 NS d.ns.nic.cz additional: a.ns.nic.cz 18000 A 194.0.12.1 additional: a.ns.nic.cz 18000 28 \040\001\006x\000\017\000\000\000\000\000\000\000\000\000\001 additional: b.ns.nic.cz 18000 A 194.0.13.1 additional: b.ns.nic.cz 18000 28 \040\001\006x\000\020\000\000\000\000\000\000\000\000\000\001 additional: d.ns.nic.cz 18000 A 193.29.206.1 additional: d.ns.nic.cz 18000 28 \040\001\006x\000\001\000\000\000\000\000\000\000\000\000\001
c.ns.nic.cz の additional がないことに注意。
$ dnsq ns ns.nic.cz 194.0.12.1
2 ns.nic.cz: 76 bytes, 1+0+1+0 records, response, authoritative, noerror query: 2 ns.nic.cz authority: nic.cz 1800 SOA a.ns.nic.cz hostmaster.nic.cz 1475167802 10800 3600 1209600 7200
1.2. c.ns.nic.cz
$ dnsq ns cz c.ns.nic.cz
2 cz: 91 bytes, 1+4+0+0 records, response, authoritative, noerror query: 2 cz answer: cz 18000 NS b.ns.nic.cz answer: cz 18000 NS d.ns.nic.cz answer: cz 18000 NS c.ns.nic.cz answer: cz 18000 NS a.ns.nic.cz
$ dnsq ns nic.cz c.ns.nic.cz
2 nic.cz: 207 bytes, 1+3+0+6 records, response, authoritative, noerror query: 2 nic.cz answer: nic.cz 1800 NS a.ns.nic.cz answer: nic.cz 1800 NS b.ns.nic.cz answer: nic.cz 1800 NS d.ns.nic.cz additional: a.ns.nic.cz 1800 A 194.0.12.1 additional: a.ns.nic.cz 1800 28 \040\001\006x\000\017\000\000\000\000\000\000\000\000\000\001 additional: b.ns.nic.cz 1800 A 194.0.13.1 additional: b.ns.nic.cz 1800 28 \040\001\006x\000\020\000\000\000\000\000\000\000\000\000\001 additional: d.ns.nic.cz 1800 A 193.29.206.1 additional: d.ns.nic.cz 1800 28 \040\001\006x\000\001\000\000\000\000\000\000\000\000\000\001
c.ns.nic.cz はnic.czのNSには現れないが、こういう返事をする。-- ToshinoriMaeno 2016-10-02 21:13:44
$ dnsq soa nic.cz c.ns.nic.cz
6 nic.cz: 254 bytes, 1+1+3+6 records, response, authoritative, noerror query: 6 nic.cz answer: nic.cz 1800 SOA a.ns.nic.cz hostmaster.nic.cz 1475167802 10800 3600 1209600 7200 authority: nic.cz 1800 NS b.ns.nic.cz authority: nic.cz 1800 NS d.ns.nic.cz authority: nic.cz 1800 NS a.ns.nic.cz additional: a.ns.nic.cz 1800 A 194.0.12.1 additional: a.ns.nic.cz 1800 28 \040\001\006x\000\017\000\000\000\000\000\000\000\000\000\001 additional: b.ns.nic.cz 1800 A 194.0.13.1 additional: b.ns.nic.cz 1800 28 \040\001\006x\000\020\000\000\000\000\000\000\000\000\000\001 additional: d.ns.nic.cz 1800 A 193.29.206.1 additional: d.ns.nic.cz 1800 28 \040\001\006x\000\001\000\000\000\000\000\000\000\000\000\001
1.3. a.ns.nic.cz
その時々で返事が異なる。
$ dnsq ns cz a.ns.nic.cz
2 cz: 91 bytes, 1+4+0+0 records, response, authoritative, noerror query: 2 cz answer: cz 18000 NS d.ns.nic.cz answer: cz 18000 NS b.ns.nic.cz answer: cz 18000 NS c.ns.nic.cz answer: cz 18000 NS a.ns.nic.cz
$ dnsq ns cz a.ns.nic.cz
2 cz: 223 bytes, 1+4+0+6 records, response, authoritative, noerror query: 2 cz answer: cz 18000 NS a.ns.nic.cz answer: cz 18000 NS b.ns.nic.cz answer: cz 18000 NS c.ns.nic.cz answer: cz 18000 NS d.ns.nic.cz additional: a.ns.nic.cz 18000 A 194.0.12.1 additional: b.ns.nic.cz 18000 A 194.0.13.1 additional: d.ns.nic.cz 18000 A 193.29.206.1 additional: a.ns.nic.cz 18000 28 \040\001\006x\000\017\000\000\000\000\000\000\000\000\000\001 additional: b.ns.nic.cz 18000 28 \040\001\006x\000\020\000\000\000\000\000\000\000\000\000\001 additional: d.ns.nic.cz 18000 28 \040\001\006x\000\001\000\000\000\000\000\000\000\000\000\001
additional に c.ns.nic.cz がないことは？
- additional sectionは付けなければならないものではないから、なくても構わない。
それにしても、気持ち悪い返答ではある。 -- ToshinoriMaeno 2016-10-02 21:27:59