DNS/watch/image.books.rakuten.co.jpについて、ここに記述してください。
RFC ignorant (CNAME chain)
$ dnsqr a image.books.rakuten.co.jp
1 image.books.rakuten.co.jp: 143 bytes, 1+3+0+0 records, response, noerror query: 1 image.books.rakuten.co.jp answer: image.books.rakuten.co.jp 3600 CNAME image.books.rakuten.co.jp.edgekey.net answer: image.books.rakuten.co.jp.edgekey.net 21600 CNAME e4545.b.akamaiedge.net answer: e4545.b.akamaiedge.net 20 A 23.0.198.113
tmaeno@:~$ DNSCACHEIP=8.8.8.8 dnsqr a image.books.rakuten.co.jp
1 image.books.rakuten.co.jp: 143 bytes, 1+3+0+0 records, response, noerror query: 1 image.books.rakuten.co.jp answer: image.books.rakuten.co.jp 988 CNAME image.books.rakuten.co.jp.edgekey.net answer: image.books.rakuten.co.jp.edgekey.net 6600 CNAME e4545.b.akamaiedge.net answer: e4545.b.akamaiedge.net 16 A 60.254.138.113
tmaeno@:~$ DNSCACHEIP=208.67.222.222 dnsqr a image.books.rakuten.co.jp
1 image.books.rakuten.co.jp: 143 bytes, 1+3+0+0 records, response, noerror query: 1 image.books.rakuten.co.jp answer: image.books.rakuten.co.jp 1446 CNAME image.books.rakuten.co.jp.edgekey.net answer: image.books.rakuten.co.jp.edgekey.net 19446 CNAME e4545.b.akamaiedge.net answer: e4545.b.akamaiedge.net 20 A 184.26.22.113
まじめにDNS検索してみると、
$ dnsq a image.books.rakuten.co.jp a.dns.jp
1 image.books.rakuten.co.jp: 187 bytes, 1+0+4+4 records, response, noerror query: 1 image.books.rakuten.co.jp authority: rakuten.co.jp 86400 NS ns05c.rakuten.co.jp authority: rakuten.co.jp 86400 NS ns04d.rakuten.co.jp authority: rakuten.co.jp 86400 NS ns03d.rakuten.co.jp authority: rakuten.co.jp 86400 NS ns01c.rakuten.co.jp additional: ns01c.rakuten.co.jp 86400 A 202.72.49.60 additional: ns03d.rakuten.co.jp 86400 A 203.190.57.223 additional: ns04d.rakuten.co.jp 86400 A 203.190.57.136 additional: ns05c.rakuten.co.jp 86400 A 202.72.49.2
tmaeno@:~$ dnsq a image.books.rakuten.co.jp ns01c.rakuten.co.jp
1 image.books.rakuten.co.jp: 302 bytes, 1+1+13+0 records, response, authoritative, noerror query: 1 image.books.rakuten.co.jp answer: image.books.rakuten.co.jp 3600 CNAME image.books.rakuten.co.jp.edgekey.net authority: . 3600000 NS g.root-servers.net authority: . 3600000 NS h.root-servers.net authority: . 3600000 NS i.root-servers.net authority: . 3600000 NS j.root-servers.net authority: . 3600000 NS k.root-servers.net authority: . 3600000 NS l.root-servers.net authority: . 3600000 NS m.root-servers.net authority: . 3600000 NS a.root-servers.net authority: . 3600000 NS b.root-servers.net authority: . 3600000 NS c.root-servers.net authority: . 3600000 NS d.root-servers.net authority: . 3600000 NS e.root-servers.net authority: . 3600000 NS f.root-servers.net
なんだろう。この返事は。
- あとは面倒なので、省略。 CNAME chain だけかどうか。