1. brau.jpを乗取る/返答

1.1. 三種類の返答

1. 委譲返答
2. NXDOMAIN 返答
3. 毒入返答

1.2. 委譲返答

毒の影響範囲が問題です。/brau.jpの返答

$ dig -t ns brau.internat.jp @127.0.0.1

; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> -t ns brau.internat.jp @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 31489
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;brau.internat.jp.              IN      NS

;; ANSWER SECTION:
brau.internat.jp.       595     IN      NS      ns.brau.jp.

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sat Aug 29 11:15:00 JST 2020
;; MSG SIZE  rcvd: 56

1.3. NXDOMAIN 返答

これが一番まとも

1.4. 毒入返答

$ dig -t ns brau.internat.jp @1.1.1.1

; <<>> DiG 9.16.1-Ubuntu <<>> -t ns brau.internat.jp @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19103
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;brau.internat.jp.              IN      NS

;; ANSWER SECTION:
brau.internat.jp.       300     IN      NS      ns.brau.internat.jp.

;; Query time: 35 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: 土  8月 29 11:53:21 JST 2020
;; MSG SIZE  rcvd: 78