DNS/毒盛/flip.e-ontap.com/上級編/AnswerNSについて、ここに記述してください。

BIND　9.12.3 では (@127.0.0.1) /unbound

• Authoritative Answer NSがキャッシュにあっても、上書きが起きることを体験する。

1. ゾーンからNS+A を取り込んでおく

$ dig -t ns flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> -t ns flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49517
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: 0f5b13054b35fb194e0d53a95c3c4984c348ef68002f588d (good)
;; QUESTION SECTION:
;flip.e-ontap.com.              IN      NS

;; ANSWER SECTION:
flip.e-ontap.com.       3371    IN      NS      ns.flip.e-ontap.com.

;; ADDITIONAL SECTION:
ns.flip.e-ontap.com.    3371    IN      A       150.42.6.1

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:34:12 JST 2019
;; MSG SIZE  rcvd: 106

tmaeno@u16:~$ dig -t a ns.flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> -t a ns.flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6405
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: 3790139c2c5153cf53c8592a5c3c498911ca8f52ad936233 (good)
;; QUESTION SECTION:
;ns.flip.e-ontap.com.           IN      A

;; ANSWER SECTION:
ns.flip.e-ontap.com.    3366    IN      A       150.42.6.1

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:34:17 JST 2019
;; MSG SIZE  rcvd: 92

2. 毒

$ dig x1.flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> x1.flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64594
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: 527224475d96ef81b3db45425c3c49c7a6f1da4930a02167 (good)
;; QUESTION SECTION:
;x1.flip.e-ontap.com.           IN      A

;; ANSWER SECTION:
x1.flip.e-ontap.com.    60      IN      A       150.42.6.1

;; Query time: 11 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:35:19 JST 2019
;; MSG SIZE  rcvd: 92

tmaeno@u16:~$ dig x2.flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> x2.flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 55609
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: 8758e9369bf8f1d360d19a685c3c49d21b89890620d8cc5e (good)
;; QUESTION SECTION:
;x2.flip.e-ontap.com.           IN      A

;; ANSWER SECTION:
x2.flip.e-ontap.com.    60      IN      A       150.42.6.5

;; Query time: 38 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:35:30 JST 2019
;; MSG SIZE  rcvd: 92

tmaeno@u16:~$ dig x3.flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> x3.flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52341
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: 39ea3464843bff17c7bc7b735c3c49da3080b6a04b54a918 (good)
;; QUESTION SECTION:
;x3.flip.e-ontap.com.           IN      A

;; ANSWER SECTION:
x3.flip.e-ontap.com.    60      IN      A       150.42.6.5

;; Query time: 11 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:35:38 JST 2019
;; MSG SIZE  rcvd: 92

3. 確認

tmaeno@u16:~$ dig +norec -t ns flip.e-ontap.com @127.0.0.1

; <<>> DiG 9.12.3 <<>> +norec -t ns flip.e-ontap.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49118
;; flags: qr ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 2

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1220
; COOKIE: d3b0b8bf17a0839d539eb45c5c3c49e9d00c2ff6063553da (good)
;; QUESTION SECTION:
;flip.e-ontap.com.              IN      NS

;; ANSWER SECTION:
flip.e-ontap.com.       3270    IN      NS      ns.flip.internot.jp.

;; ADDITIONAL SECTION:
ns.flip.internot.jp.    86377   IN      A       150.42.6.5

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: 月  1月 14 17:35:53 JST 2019
;; MSG SIZE  rcvd: 122