1. jp.sharp ゾーンを探す
Contents
1.1. sharp TLD
$dig -t ns sharp @a.root-servers.net ;; AUTHORITY SECTION: sharp. 172800 IN NS l.gmoregistry.net. sharp. 172800 IN NS a.gmoregistry.net. sharp. 172800 IN NS b.gmoregistry.net. sharp. 172800 IN NS k.gmoregistry.net.
$dig -t ns jp.sharp @a.gmoregistry.net ;; AUTHORITY SECTION: jp.sharp. 86400 IN NS ns1.sharp.co.jp. jp.sharp. 86400 IN NS tg1.sharp.co.jp.
1.2. NS query
ところが、こんな返事が返る。
$ dig -t ns jp.sharp @ns1.sharp.co.jp ; <<>> DiG 9.11.3-1ubuntu1.14-Ubuntu <<>> -t ns jp.sharp @ns1.sharp.co.jp ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10483 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ; COOKIE: cc5857609cf751b06079be746105e9ec75770ab967235a9e (good) ;; QUESTION SECTION: ;jp.sharp. IN NS ;; ANSWER SECTION: jp.sharp. 300 IN CNAME ualsharp.hs.llnwd.net. ;; Query time: 27 msec ;; SERVER: 61.214.248.154#53(61.214.248.154) ;; WHEN: Sun Aug 01 09:25:16 JST 2021 ;; MSG SIZE rcvd: 100
1.3. jp.sharp ゾーンはない
CNAME レコードはなにか。