DNS/KnotResolver/CNAME+NS/xw.qmail.jpについて、ここに記述してください。

おかしな設定をしてみた。(tinydnsなら可能ｗ）

$ kdig -t ns xw.qmail.jp @127.0.0.3 

;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 17293
;; Flags: qr rd ra; QUERY: 1; ANSWER: 2; AUTHORITY: 0; ADDITIONAL: 0

;; QUESTION SECTION:
;; xw.qmail.jp.                 IN      NS

;; ANSWER SECTION:
xw.qmail.jp.            300     IN      NS      b.ns.xw.qmail.jp.
xw.qmail.jp.            86400   IN      CNAME   www.qmail.jp.

;; Received 66 B
;; Time 2015-12-05 08:06:05 JST
;; From 127.0.0.3@53(UDP) in 43.1 ms

$ kdig -t cname xw.qmail.jp @127.0.0.3 

;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 59746
;; Flags: qr rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 0

;; QUESTION SECTION:
;; xw.qmail.jp.                 IN      CNAME

;; ANSWER SECTION:
xw.qmail.jp.            86373   IN      CNAME   www.qmail.jp.

;; Received 47 B
;; Time 2015-12-05 08:06:32 JST
;; From 127.0.0.3@53(UDP) in 0.3 ms

$ sh run 

[hint] reading '/etc/hosts'
[hint] loaded 17 hints
[system] interactive mode
> [plan] plan 'xw.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: 7 ms
[resl]   => querying: '14.192.44.5' score: 10 zone cut: 'qmail.jp.' m12n: 'XW.qmaiL.jp.' type: 'NS'
[iter]   <= referral response, follow
[resl]   <= server: '14.192.44.5' rtt: 15 ms
[resl]   => querying: '14.192.44.29' score: 10 zone cut: 'xw.qmail.jp.' m12n: 'Xw.Qmail.jp.' type: 'NS'
[iter]   <= rcode: NOERROR
[resl]   <= server: '14.192.44.29' rtt: 12 ms
[resl] finished: 4, queries: 1, mempool: 16400 B
[plan] plan 'xw.qmail.jp.' type 'CNAME'
[ rc ]   => satisfied from cache
[iter]   <= rcode: NOERROR
[resl] finished: 4, queries: 1, mempool: 16400 B