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
}}}