DNS/返答/NXDOMAIN/Knot-resolverについて、ここに記述してください。
$ sh run [hint] reading '/etc/hosts' [hint] loaded 34 hints [cache] purging cache [system] interactive mode
$ dig -t ns xxxxxxx.ns.qmail.jp @127.0.0.3 ; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> -t ns xxxxxxx.ns.qmail.jp @127.0.0.3 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 47423 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;xxxxxxx.ns.qmail.jp. IN NS ;; AUTHORITY SECTION: qmail.jp. 2560 IN SOA a.ns.qmail.jp. hostmaster.m.qmail.jp. 1454758295 16384 2048 1048576 2560 ;; Query time: 35 msec ;; SERVER: 127.0.0.3#53(127.0.0.3) ;; WHEN: Sun Mar 13 09:02:39 JST 2016 ;; MSG SIZE rcvd: 99
> [plan] plan 'xxxxxxx.ns.qmail.jp.' type 'NS' [resl] => using root hints [resl] => querying: '202.12.27.33' score: 10 zone cut: '.' m12n: 'Jp.' type: 'NS' [resl] optional: '199.7.83.42' score: 10 zone cut: '.' m12n: 'Jp.' type: 'NS' [resl] optional: '193.0.14.129' score: 10 zone cut: '.' m12n: 'Jp.' type: 'NS' [resl] optional: '192.58.128.30' score: 10 zone cut: '.' m12n: 'Jp.' type: 'NS' [iter] <= referral response, follow [resl] <= server: '202.12.27.33' rtt: 6 ms [resl] => querying: '203.119.40.1' score: 10 zone cut: 'jp.' m12n: 'QmAiL.JP.' type: 'NS' [resl] optional: '150.100.6.8' score: 10 zone cut: 'jp.' m12n: 'QmAiL.JP.' type: 'NS' [resl] optional: '192.50.43.53' score: 10 zone cut: 'jp.' m12n: 'QmAiL.JP.' type: 'NS' [resl] optional: '210.138.175.244' score: 10 zone cut: 'jp.' m12n: 'QmAiL.JP.' type: 'NS' [iter] <= referral response, follow [resl] <= server: '203.119.40.1' rtt: 5 ms [resl] => querying: '14.192.44.5' score: 10 zone cut: 'qmail.jp.' m12n: 'ns.QMAiL.jP.' type: 'NS' [iter] <= rcode: NOERROR [iter] <= found cut, retrying with non-minimized name [ pc ] => answer cached for TTL=900 [resl] <= server: '14.192.44.5' rtt: 11 ms [resl] => querying: '14.192.44.5' score: 11 zone cut: 'qmail.jp.' m12n: 'XXxXXXX.NS.qMaIL.Jp.' type: 'NS' [iter] <= rcode: NXDOMAIN [ pc ] => answer cached for TTL=900 [resl] <= server: '14.192.44.5' rtt: 10 ms [resl] finished: 4, queries: 1, mempool: 32800 B
$ dnsq ns xxxxxxx.ns.qmail.jp 127.0.0.3 2 xxxxxxx.ns.qmail.jp: 88 bytes, 1+0+1+0 records, response, weird ra, nxdomain query: 2 xxxxxxx.ns.qmail.jp authority: qmail.jp 2340 SOA a.ns.qmail.jp hostmaster.m.qmail.jp 1454758295 16384 2048 1048576 2560
[plan] plan 'xxxxxxx.ns.qmail.jp.' type 'NS' [ pc ] => satisfied from cache [iter] <= rcode: NXDOMAIN [resl] finished: 4, queries: 1, mempool: 32800 B
$ dig -t ns xxxxxxx1.ns.qmail.jp @127.0.0.3 ; <<>> DiG 9.9.5-3ubuntu0.8-Ubuntu <<>> -t ns xxxxxxx1.ns.qmail.jp @127.0.0.3 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 4463 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;xxxxxxx1.ns.qmail.jp. IN NS ;; AUTHORITY SECTION: qmail.jp. 2560 IN SOA a.ns.qmail.jp. hostmaster.m.qmail.jp. 1454758295 16384 2048 1048576 2560 ;; Query time: 14 msec ;; SERVER: 127.0.0.3#53(127.0.0.3) ;; WHEN: Sun Mar 13 09:09:32 JST 2016 ;; MSG SIZE rcvd: 100
[plan] plan 'xxxxxxx1.ns.qmail.jp.' type 'NS' [resl] => querying: '14.192.44.5' score: 11 zone cut: 'qmail.jp.' m12n: 'XxxXxXx1.nS.QMaIL.jP.' type: 'NS' [iter] <= rcode: NXDOMAIN [ pc ] => answer cached for TTL=900 [resl] <= server: '14.192.44.5' rtt: 13 ms [resl] finished: 4, queries: 1, mempool: 32800 B