1. whois
2. history
$ dig -t ns rehappy.jp @ns1.xserver.jp. ; <<>> DiG 9.18.18-0ubuntu0.22.04.1-Ubuntu <<>> -t ns rehappy.jp @ns1.xserver.jp. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 53621 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1680 ; NSID: 6e 73 31 2e 78 73 65 72 76 65 72 2e 6a 70 ("ns1.xserver.jp") ;; QUESTION SECTION: ;rehappy.jp. IN NS ;; ANSWER SECTION: rehappy.jp. 86400 IN CNAME rehappy.jimdo.com. ;; AUTHORITY SECTION: jimdo.com. 3600 IN SOA ns1.xserver.jp. root.xserver.jp. 0 10800 3600 604800 3600 ;; Query time: 15 msec ;; SERVER: 202.226.36.246#53(ns1.xserver.jp.) (UDP) ;; WHEN: Wed Nov 15 10:42:56 JST 2023 ;; MSG SIZE rcvd: 141