DNS/Cloudflare/qmail.jp/不良について、ここに記述してください。

$ dig -t ns gs.qmail.jp @sri.ns.cloudflare.com

返事がおかしい。qtype NS のときに CNAMEを答えない。

• CNAMEの存在を知らないわけではない。-- ToshinoriMaeno 2019-12-23 02:03:28

1. 正規の返事

$ dig -t ns gs.qmail.jp @a.ns.qmail.jp

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> -t ns gs.qmail.jp @a.ns.qmail.jp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38070
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

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

;; ANSWER SECTION:
gs.qmail.jp.            3600    IN      CNAME   www.qmail.jp.

;; AUTHORITY SECTION:
qmail.jp.               259200  IN      NS      b.ns.qmail.jp.

;; ADDITIONAL SECTION:
b.ns.qmail.jp.          172800  IN      A       14.192.44.5

;; Query time: 11 msec
;; SERVER: 14.192.44.5#53(14.192.44.5)
;; WHEN: Mon Dec 23 10:51:09 JST 2019
;; MSG SIZE  rcvd: 82

2. CF返答

$ dig -t ns gs.qmail.jp @sri.ns.cloudflare.com

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> -t ns gs.qmail.jp @sri.ns.cloudflare.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43400
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;gs.qmail.jp.                   IN      NS

;; AUTHORITY SECTION:
qmail.jp.               3600    IN      SOA     rachel.ns.cloudflare.com. dns.cloudflare.com. 2032872762 10000 2400 604800 3600

;; Query time: 11 msec
;; SERVER: 173.245.59.234#53(173.245.59.234)
;; WHEN: Mon Dec 23 10:50:36 JST 2019
;; MSG SIZE  rcvd: 104

$ dig -t a gs.qmail.jp @a.ns.qmail.jp

; <<>> DiG 9.11.3-1ubuntu1.11-Ubuntu <<>> -t a gs.qmail.jp @a.ns.qmail.jp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33442
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;gs.qmail.jp.                   IN      A

;; ANSWER SECTION:
gs.qmail.jp.            3600    IN      CNAME   www.qmail.jp.

;; AUTHORITY SECTION:
qmail.jp.               259200  IN      NS      b.ns.qmail.jp.

;; ADDITIONAL SECTION:
b.ns.qmail.jp.          172800  IN      A       14.192.44.5

;; Query time: 12 msec
;; SERVER: 14.192.44.5#53(14.192.44.5)
;; WHEN: Mon Dec 23 10:59:54 JST 2019
;; MSG SIZE  rcvd: 82