1. DNS/返答/NXDOMAIN/qmail.jp

について、ここに記述してください。

1.1. IIJ リゾルバーの返答

この返事は変だった。(現在はNOERRORになる。)

%dig ns.qmail.jp @ns4.iij.ad.jp                                         ~

; <<>> DiG 9.10.4-P6 <<>> ns.qmail.jp @ns4.iij.ad.jp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 27434
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;ns.qmail.jp.                   IN      A

;; AUTHORITY SECTION:
qmail.jp.               2383    IN      SOA     a.ns.qmail.jp. hostmaster.m.qmail.jp. 1507365818 16384 2048 1048576 2560

;; Query time: 8 msec
;; SERVER: 202.232.2.38#53(202.232.2.38)
;; WHEN: Sun Oct 08 15:51:34 JST 2017
;; MSG SIZE  rcvd: 91

%dig a.ns.qmail.jp @ns4.iij.ad.jp                                       ~

; <<>> DiG 9.10.4-P6 <<>> a.ns.qmail.jp @ns4.iij.ad.jp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3859
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;a.ns.qmail.jp.                 IN      A

;; ANSWER SECTION:
a.ns.qmail.jp.          3394    IN      A       14.192.44.5

;; Query time: 4 msec
;; SERVER: 202.232.2.38#53(202.232.2.38)
;; WHEN: Sun Oct 08 15:52:03 JST 2017
;; MSG SIZE  rcvd: 58