1. watchNS/oss.jp

zone apex に NS+SOA+CNAME (しかもdjbdnsらしいこと） 

oss.jp.                 2560    IN      SOA     ns1.oss.jp. hostmaster.oss.jp. 1335450384 16384 2048 1048576 2560
oss.jp.                 86400   IN      CNAME   oss.jp.s3-website-ap-northeast-1.amazonaws.com.

../oss.jp-old

$ dnsq ns oss.jp a.dns.jp 

2 oss.jp:
100 bytes, 1+0+2+2 records, response, noerror
query: 2 oss.jp
authority: oss.jp 86400 NS 
authority: oss.jp 86400 NS ns2.todo.ne.jp
additional: ns1.todo.ne.jp 86400 A 203.174.74.40
additional: ns2.todo.ne.jp 86400 A 203.174.74.36

$ dnsq ns oss.jp 203.174.74.40 

2 oss.jp:
152 bytes, 1+3+0+2 records, response, authoritative, noerror
query: 2 oss.jp
answer: oss.jp 259200 NS ns1.oss.jp
answer: oss.jp 259200 NS ns2.oss.jp
answer: oss.jp 86400 CNAME oss.jp.s3-website-ap-northeast-1.amazonaws.com
additional: ns1.oss.jp 259200 A 203.174.74.40
additional: ns2.oss.jp 259200 A 203.174.74.36

$ dnsq soa oss.jp ns1.todo.ne.jp 

6 oss.jp:
199 bytes, 1+2+2+2 records, response, authoritative, noerror
query: 6 oss.jp
answer: oss.jp 2560 SOA ns1.oss.jp hostmaster.oss.jp 1335450384 16384 2048 1048576 2560
answer: oss.jp 86400 CNAME oss.jp.s3-website-ap-northeast-1.amazonaws.com
authority: oss.jp 259200 NS ns1.oss.jp
authority: oss.jp 259200 NS ns2.oss.jp
additional: ns1.oss.jp 259200 A 203.174.74.40
additional: ns2.oss.jp 259200 A 203.174.74.36

2. MX

$ dig -t mx oss.jp @8.8.8.8 

; <<>> DiG 9.9.5-3ubuntu0.13-Ubuntu <<>> -t mx oss.jp @8.8.8.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 25954
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;oss.jp.                                IN      MX

;; ANSWER SECTION:
oss.jp.                 86399   IN      CNAME   oss.jp.s3-website-ap-northeast-1.amazonaws.com.
oss.jp.s3-website-ap-northeast-1.amazonaws.com. 59 IN CNAME s3-website-ap-northeast-1.amazonaws.com.

;; AUTHORITY SECTION:
s3-website-ap-northeast-1.amazonaws.com. 899 IN SOA ns-1643.awsdns-13.co.uk. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400

;; Query time: 261 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Feb 21 22:46:25 JST 2017
;; MSG SIZE  rcvd: 193