watchNS/web.fc2.comについて、ここに記述してください。

web.fc2.com (zone)のNSはmdns1.fc2.comなどである。

ところが、... -- ToshinoriMaeno 2018-02-13 00:20:51

NSレコードに注目

%dig -t ns web.fc2.com @a.gtld-servers.net                     ~/dnsq/0205

; <<>> DiG 9.11.2 <<>> -t ns web.fc2.com @a.gtld-servers.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43034
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;web.fc2.com.                   IN      NS

;; AUTHORITY SECTION:
fc2.com.                172800  IN      NS      ns-214.awsdns-26.com.
fc2.com.                172800  IN      NS      ns-616.awsdns-13.net.
fc2.com.                172800  IN      NS      ns-1834.awsdns-37.co.uk.
fc2.com.                172800  IN      NS      ns-1489.awsdns-58.org.

;; ADDITIONAL SECTION:
ns-214.awsdns-26.com.   172800  IN      A       205.251.192.214
ns-616.awsdns-13.net.   172800  IN      A       205.251.194.104

;; Query time: 122 msec
;; SERVER: 192.5.6.30#53(192.5.6.30)
;; WHEN: Tue Feb 13 09:06:59 JST 2018
;; MSG SIZE  rcvd: 209

%dig -t ns web.fc2.com @ns-214.awsdns-26.com.                  ~/dnsq/0205

; <<>> DiG 9.11.2 <<>> -t ns web.fc2.com @ns-214.awsdns-26.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 12679
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 3, ADDITIONAL: 4
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;web.fc2.com.                   IN      NS

;; AUTHORITY SECTION:
web.fc2.com.            86400   IN      NS      mdns1.fc2.com.
web.fc2.com.            86400   IN      NS      mdns2.fc2.com.
web.fc2.com.            86400   IN      NS      mdns3.fc2.com.

;; ADDITIONAL SECTION:
mdns1.fc2.com.          300     IN      A       54.218.49.223
mdns2.fc2.com.          300     IN      A       54.244.4.177
mdns3.fc2.com.          300     IN      A       54.213.109.64

;; Query time: 88 msec
;; SERVER: 205.251.192.214#53(205.251.192.214)
;; WHEN: Tue Feb 13 09:07:42 JST 2018
;; MSG SIZE  rcvd: 148

1. 最終返答

Unbound harden-referral-path はこれをどう処理しているのか。-- ToshinoriMaeno 2018-02-13 00:09:52

%dig -t ns web.fc2.com @mdns1.fc2.com.                         ~/dnsq/0205

; <<>> DiG 9.11.2 <<>> -t ns web.fc2.com @mdns1.fc2.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 48289
;; flags: qr aa; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;web.fc2.com.                   IN      NS

;; AUTHORITY SECTION:
web.fc2.com.            86400   IN      SOA     mdns1.fc2.com.web.fc2.com. info.smartcgi.com. 172 28800 7200 604480 600

;; Query time: 139 msec
;; SERVER: 54.218.49.223#53(54.218.49.223)
;; WHEN: Tue Feb 13 09:08:23 JST 2018
;; MSG SIZE  rcvd: 93

2. 親子同居だが

本当の親 fc2.comへの委譲はaws上のホストなのだ。

%dig -t ns fc2.com @mdns1.fc2.com.                             ~/dnsq/0205

; <<>> DiG 9.11.2 <<>> -t ns fc2.com @mdns1.fc2.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47364
;; flags: qr aa rd ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;fc2.com.                       IN      NS

;; ANSWER SECTION:
fc2.com.                86400   IN      NS      mdns1.fc2.com.
fc2.com.                86400   IN      NS      mdns2.fc2.com.
fc2.com.                86400   IN      NS      mdns3.fc2.com.

;; ADDITIONAL SECTION:
mdns1.fc2.com.          86400   IN      A       208.71.107.72
mdns2.fc2.com.          86400   IN      A       208.71.107.73
mdns3.fc2.com.          86400   IN      A       208.71.107.74

;; Query time: 138 msec
;; SERVER: 54.218.49.223#53(54.218.49.223)
;; WHEN: Tue Feb 13 09:10:00 JST 2018
;; MSG SIZE  rcvd: 133

3. rootからの委譲はこっち

%dig -t ns fc2.com @ns-214.awsdns-26.com.                      ~/dnsq/0205

; <<>> DiG 9.11.2 <<>> -t ns fc2.com @ns-214.awsdns-26.com.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20961
;; flags: qr aa rd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;fc2.com.                       IN      NS

;; ANSWER SECTION:
fc2.com.                86400   IN      NS      ns-1489.awsdns-58.org.
fc2.com.                86400   IN      NS      ns-1834.awsdns-37.co.uk.
fc2.com.                86400   IN      NS      ns-214.awsdns-26.com.
fc2.com.                86400   IN      NS      ns-616.awsdns-13.net.

;; Query time: 97 msec
;; SERVER: 205.251.192.214#53(205.251.192.214)
;; WHEN: Tue Feb 13 09:12:36 JST 2018
;; MSG SIZE  rcvd: 173

4. そして

子が親を乗っ取ることにならないか。(ならない。w) まともなリゾルバーであれば。-- ToshinoriMaeno 2018-02-13 00:45:39

$ dig -t ns av-photograph.com @mdns1.fc2.com

; <<>> DiG 9.12.0 <<>> -t ns av-photograph.com @mdns1.fc2.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26770
;; flags: qr aa rd ad; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 4
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;av-photograph.com.             IN      NS

;; ANSWER SECTION:
av-photograph.com.      86400   IN      CNAME   happysmile0418.blog.fc2.com.

;; AUTHORITY SECTION:
fc2.com.                86400   IN      NS      mdns1.fc2.com.
fc2.com.                86400   IN      NS      mdns2.fc2.com.
fc2.com.                86400   IN      NS      mdns3.fc2.com.

;; ADDITIONAL SECTION:
happysmile0418.blog.fc2.com. 86400 IN   CNAME   blog-cach-ElasticL-HJNP94VKMIH2-1363093325.ap-northeast-1.elb.amazonaws.com.
mdns1.fc2.com.          86400   IN      A       208.71.107.72
mdns2.fc2.com.          86400   IN      A       208.71.107.73
mdns3.fc2.com.          86400   IN      A       208.71.107.74

;; Query time: 140 msec
;; SERVER: 54.218.49.223#53(54.218.49.223)
;; WHEN: Tue Feb 13 09:42:42 JST 2018
;; MSG SIZE  rcvd: 267