NS+CNAME 型返答をもらっての処理
https://dnschecker.org/#A/yaizawa.jp (解決)
1. CNAME 優先
1.1.1.1,
$ dig -t ns yaizawa.jp @8.8.8.8 ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t ns yaizawa.jp @8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43166 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;yaizawa.jp. IN NS ;; ANSWER SECTION: yaizawa.jp. 21600 IN CNAME amaterasu.yaizawa.jp. ;; AUTHORITY SECTION: yaizawa.jp. 1800 IN SOA ns0.yaizawa.jp. hostmaster.yaizawa.jp. 1639921421 16384 2048 1048576 2560 ;; Query time: 55 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP) ;; WHEN: Sun Oct 30 13:35:37 JST 2022 ;; MSG SIZE rcvd: 114
2. 9.9.9.9
NSも参照するようだ。
$ dig -tns yaizawa.jp @9.9.9.9
; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -tns yaizawa.jp @9.9.9.9
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53625
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
; NSID: 72 65 73 31 31 30 2e 71 68 6e 64 31 2e 72 72 64 6e 73 2e 70 63 68 2e 6e 65 74 ("res110.qhnd1.rrdns.pch.net")
;; QUESTION SECTION:
;yaizawa.jp. IN NS
;; ANSWER SECTION:
yaizawa.jp. 43200 IN CNAME amaterasu.yaizawa.jp.
yaizawa.jp. 43200 IN NS ns1.yaizawa.jp.
yaizawa.jp. 43200 IN NS ns0.yaizawa.jp.
;; Query time: 1576 msec
;; SERVER: 9.9.9.9#53(9.9.9.9) (UDP)
;; WHEN: Sun Oct 30 14:13:59 JST 2022
;; MSG SIZE rcvd: 129
3. NS
$ dig -t ns yaizawa.jp @ns0.yaizawa.jp ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t ns yaizawa.jp @ns0.yaizawa.jp ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19632 ;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 2 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;yaizawa.jp. IN NS ;; ANSWER SECTION: yaizawa.jp. 259200 IN NS ns0.yaizawa.jp. yaizawa.jp. 259200 IN NS ns1.yaizawa.jp. yaizawa.jp. 86400 IN CNAME amaterasu.yaizawa.jp. ;; ADDITIONAL SECTION: ns0.yaizawa.jp. 259200 IN A 133.125.35.31 ns1.yaizawa.jp. 259200 IN A 49.212.147.73 ;; Query time: 15 msec ;; SERVER: 133.125.35.31#53(ns0.yaizawa.jp) (UDP) ;; WHEN: Sun Oct 30 13:34:15 JST 2022 ;; MSG SIZE rcvd: 120
4. SOA
$ dig -t soa yaizawa.jp @ns0.yaizawa.jp ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t soa yaizawa.jp @ns0.yaizawa.jp ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12438 ;; flags: qr aa rd; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 2 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;yaizawa.jp. IN SOA ;; ANSWER SECTION: yaizawa.jp. 2560 IN SOA ns0.yaizawa.jp. hostmaster.yaizawa.jp. 1639921421 16384 2048 1048576 2560 yaizawa.jp. 86400 IN CNAME amaterasu.yaizawa.jp. ;; AUTHORITY SECTION: yaizawa.jp. 259200 IN NS ns0.yaizawa.jp. yaizawa.jp. 259200 IN NS ns1.yaizawa.jp. ;; ADDITIONAL SECTION: ns0.yaizawa.jp. 259200 IN A 133.125.35.31 ns1.yaizawa.jp. 259200 IN A 49.212.147.73 ;; Query time: 19 msec ;; SERVER: 133.125.35.31#53(ns0.yaizawa.jp) (UDP) ;; WHEN: Sun Oct 30 13:32:42 JST 2022 ;; MSG SIZE rcvd: 167
5. 8.8.8.8
1.1.1.1, 9.9.9.9 も同様
$ dig -t a yaizawa.jp @8.8.8.8 ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t a yaizawa.jp @8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54151 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;yaizawa.jp. IN A ;; ANSWER SECTION: yaizawa.jp. 21556 IN CNAME amaterasu.yaizawa.jp. amaterasu.yaizawa.jp. 21600 IN A 133.125.35.31 ;; Query time: 23 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP) ;; WHEN: Sun Oct 30 13:36:20 JST 2022 ;; MSG SIZE rcvd: 79