1. DNS/CNAME/8.8.8.8
NS query に cname を返す。どう解釈すればいいのだろう。
SERVFAILにしない理由はなにか。-- ToshinoriMaeno 2022-10-27 05:19:48
$ dig -t ns odns.info @8.8.8.8
; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t ns odns.info @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59924
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
; NSID: 67 70 64 6e 73 2d 6e 72 74 ("gpdns-nrt")
;; QUESTION SECTION:
;odns.info. IN NS
;; ANSWER SECTION:
odns.info. 21600 IN CNAME moin.odns.info.
;; AUTHORITY SECTION:
odns.info. 1800 IN SOA a.ns.odns.info. hostmaster.odns.info. 1666842611 16384 2048 1048576 2560
;; Query time: 28 msec
;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP)
;; WHEN: Thu Oct 27 13:34:33 JST 2022
;; MSG SIZE rcvd: 122
$ dig mmm.dnsz.org @8.8.8.8 ; <<>> DiG 9.16.1-Ubuntu <<>> mmm.dnsz.org @8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58551 ;; flags: qr rd ra cd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;mmm.dnsz.org. IN A ;; ANSWER SECTION: mmm.dnsz.org. 3599 IN CNAME mmm.qmail.jp. ;; AUTHORITY SECTION: qmail.jp. 899 IN SOA a.ns.qmail.jp. hostmaster.m.qmail.jp. 1628169048 16384 2048 1048576 900 ;; Query time: 28 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: 月 8月 09 11:59:46 JST 2021 ;; MSG SIZE rcvd: 121