1. DNS/返答/NXDOMAIN/awsdns

NXDOMAIN 返答は返るが、下部ドメインが存在する。 DNS/NXDOMAIN/awsdns

• watchA/awsdns/aist.go.jp/risec

https://forums.aws.amazon.com/thread.jspa?threadID=269116

AWS DNS services break query name minimisation (DNS privacy)
Posted by: rijswijk
Posted on: Dec 9, 2017 5:34 AM

Essentially, the cause of the issue is that AWS authoritative DNS servers incorrectly return an NXDOMAIN response to queries for empty non-terminal domains (domain names that contain multiple labels within a single DNS zone).

修正されているようだ。-- ToshinoriMaeno 2018-08-27 13:06:15

• 誤解だった。NXDOMAINを返す例がある。

$ dig +norecurse A prod.ws.fdmg.org @ns-1372.awsdns-43.org.

; <<>> DiG 9.12.1 <<>> +norecurse A prod.ws.fdmg.org @ns-1372.awsdns-43.org.
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26487
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;prod.ws.fdmg.org.              IN      A

;; AUTHORITY SECTION:
prod.ws.fdmg.org.       300     IN      NS      ns-1206.awsdns-22.org.
prod.ws.fdmg.org.       300     IN      NS      ns-1844.awsdns-38.co.uk.
prod.ws.fdmg.org.       300     IN      NS      ns-320.awsdns-40.com.
prod.ws.fdmg.org.       300     IN      NS      ns-903.awsdns-48.net.

;; Query time: 6 msec
;; SERVER: 205.251.197.92#53(205.251.197.92)
;; WHEN: Mon Aug 27 21:57:34 JST 2018
;; MSG SIZE  rcvd: 182