NS queryにはNSだけを答える。しかし、CNAME RRも存在している。
1. whois
[Domain Name] MEITRACK.JP [Registrant] Meitrack Group [Name Server] a.dnspod.com [Name Server] b.dnspod.com [Name Server] c.dnspod.com [Signing Key] [Created on] 2017/10/01 [Expires on] 2022/10/31 [Status] Active [Last Updated] 2021/11/01 01:05:11 (JST)
2. history
$ dig -t ns meitrack.jp @b.dnspod.com ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t ns meitrack.jp @b.dnspod.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9105 ;; flags: qr aa rd; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ;; QUESTION SECTION: ;meitrack.jp. IN NS ;; ANSWER SECTION: meitrack.jp. 86400 IN NS c.dnspod.com. meitrack.jp. 86400 IN NS a.dnspod.com. meitrack.jp. 86400 IN NS b.dnspod.com. ;; Query time: 199 msec ;; SERVER: 157.148.62.121#53(b.dnspod.com) (UDP) ;; WHEN: Sun Oct 30 16:37:14 JST 2022 ;; MSG SIZE rcvd: 118
$ dig -t a meitrack.jp @b.dnspod.com ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t a meitrack.jp @b.dnspod.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41661 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ;; QUESTION SECTION: ;meitrack.jp. IN A ;; ANSWER SECTION: meitrack.jp. 600 IN CNAME url.dnspod.com. ;; AUTHORITY SECTION: meitrack.jp. 86400 IN NS c.dnspod.com. meitrack.jp. 86400 IN NS a.dnspod.com. meitrack.jp. 86400 IN NS b.dnspod.com. ;; Query time: 155 msec ;; SERVER: 157.148.62.121#53(b.dnspod.com) (UDP) ;; WHEN: Sun Oct 30 16:37:45 JST 2022 ;; MSG SIZE rcvd: 146
$ dig -t cname meitrack.jp @b.dnspod.com ; <<>> DiG 9.18.1-1ubuntu1.2-Ubuntu <<>> -t cname meitrack.jp @b.dnspod.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 46699 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ;; QUESTION SECTION: ;meitrack.jp. IN CNAME ;; ANSWER SECTION: meitrack.jp. 600 IN CNAME url.dnspod.com. ;; AUTHORITY SECTION: meitrack.jp. 86400 IN NS c.dnspod.com. meitrack.jp. 86400 IN NS a.dnspod.com. meitrack.jp. 86400 IN NS b.dnspod.com. ;; Query time: 147 msec ;; SERVER: 157.148.62.121#53(b.dnspod.com) (UDP) ;; WHEN: Sun Oct 30 16:35:07 JST 2022 ;; MSG SIZE rcvd: 146