watchAAAA/gitbook.comについて、ここに記述してください。
$ dig -t aaaa cdn.gitbook.com @ns1.gitbook.me. ; <<>> DiG 9.11.1 <<>> -t aaaa cdn.gitbook.com @ns1.gitbook.me. ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 60579 ;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;cdn.gitbook.com. IN AAAA ;; ANSWER SECTION: cdn.gitbook.com. 3600 IN A 128.199.158.79 ;; Query time: 218 msec ;; SERVER: 107.170.136.67#53(107.170.136.67) ;; WHEN: Tue Jun 13 17:00:08 JST 2017 ;; MSG SIZE rcvd: 64
query type AAAAの問い合わせにAを答えてくる。
$ dnsq 28 cdn.gitbook.com ns1.gitbook.me 28 cdn.gitbook.com: 64 bytes, 1+1+0+0 records, response, noerror query: 28 cdn.gitbook.com answer: cdn.gitbook.com 3600 A 128.199.158.79
BIND 9.11.1 は
$ dig -t aaaa cdn.gitbook.com @127.0.0.1 ; <<>> DiG 9.11.1 <<>> -t aaaa cdn.gitbook.com @127.0.0.1 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 7582 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ; COOKIE: d63deaa516020b1cf52967fd593f9fc9f0b49fc1fb32fd4f (good) ;; QUESTION SECTION: ;cdn.gitbook.com. IN AAAA ;; Query time: 390 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Tue Jun 13 17:18:17 JST 2017 ;; MSG SIZE rcvd: 72