1. whois
返答が異なるのは複数のフロントエンド(バックエンドかも)を疑わせる。
$ dig ns rumias7k.com @mdns1.fc2.com ; <<>> DiG 9.18.28-0ubuntu0.24.04.1-Ubuntu <<>> ns rumias7k.com @mdns1.fc2.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 43231 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;rumias7k.com. IN NS ;; Query time: 137 msec ;; SERVER: 208.71.106.223#53(mdns1.fc2.com) (UDP) ;; WHEN: Mon Sep 09 12:46:03 JST 2024 ;; MSG SIZE rcvd: 30 tmaeno@maeno:~$ dig ns rumias7k.com @mdns1.fc2.com ; <<>> DiG 9.18.28-0ubuntu0.24.04.1-Ubuntu <<>> ns rumias7k.com @mdns1.fc2.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53410 ;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;rumias7k.com. IN NS ;; AUTHORITY SECTION: rumias7k.com. 86400 IN SOA ns.rumias7k.com. mail.rumias7k.com. 1 28800 7200 604480 86400 ;; Query time: 139 msec ;; SERVER: 208.71.106.222#53(mdns1.fc2.com) (UDP) ;; WHEN: Mon Sep 09 12:46:14 JST 2024 ;; MSG SIZE rcvd: 74