watchNS/pixiv.netについて、ここに記述してください。

   Domain Name: PIXIV.NET
   Registrar: KEY-SYSTEMS GMBH
   Whois Server: whois.rrpproxy.net
   Referral URL: http://www.key-systems.net
   Name Server: NS1.PIXIV.NET
   Name Server: NS2.PIXIV.NET
   Status: ok
   Updated Date: 20-may-2011
   Creation Date: 16-jul-2007
   Expiration Date: 16-jul-2019

1. 04-30

pixiv.net.              172800  IN      NS      ns1.pixiv.net.
pixiv.net.              172800  IN      NS      ns2.pixiv.net.

;; ADDITIONAL SECTION:
ns1.pixiv.net.          172800  IN      A       210.140.131.236
ns2.pixiv.net.          172800  IN      A       210.140.131.238

2. pixiv.net

$ dnsq any pixiv.net a.gtld-servers.net

255 pixiv.net:
95 bytes, 1+0+2+2 records, response, noerror
query: 255 pixiv.net
authority: pixiv.net 172800 NS ns1.pixiv.net
authority: pixiv.net 172800 NS ns2.pixiv.net
additional: ns1.pixiv.net 172800 A 210.168.27.46
additional: ns2.pixiv.net 172800 A 210.168.27.79

$ dnsqr a pixiv.net

1 pixiv.net:
191 bytes, 1+6+2+2 records, response, noerror
query: 1 pixiv.net
answer: pixiv.net 240 A 113.33.39.195
answer: pixiv.net 240 A 125.100.191.29
answer: pixiv.net 240 A 210.168.27.16
answer: pixiv.net 240 A 210.168.27.49
answer: pixiv.net 240 A 210.168.27.81
answer: pixiv.net 240 A 210.168.27.106
authority: pixiv.net 240 NS ns1.pixiv.net
authority: pixiv.net 240 NS ns2.pixiv.net
additional: ns1.pixiv.net 240 A 210.168.27.46
additional: ns2.pixiv.net 240 A 210.168.27.79

TTLが短い。NSレコードが問題だ。

3. 旧DNS

$ dnsq any pixiv.net dns1.name-services.com

255 pixiv.net:
328 bytes, 1+8+0+5 records, response, authoritative, noerror
query: 255 pixiv.net
answer: pixiv.net 3600 A 69.64.147.243
answer: pixiv.net 3600 MX 10 p.nsm.ctmail.com
answer: pixiv.net 3600 SOA dns1.name-services.com info.name-services.com 2002050701 10001 1801 604801 181
answer: pixiv.net 3600 NS dns1.name-services.com
answer: pixiv.net 3600 NS dns2.name-services.com
answer: pixiv.net 3600 NS dns3.name-services.com
answer: pixiv.net 3600 NS dns4.name-services.com
answer: pixiv.net 3600 NS dns5.name-services.com
additional: dns1.name-services.com 3600 A 98.124.192.1
additional: dns2.name-services.com 3600 A 98.124.197.1
additional: dns3.name-services.com 3600 A 98.124.193.1
additional: dns4.name-services.com 3600 A 98.124.194.1
additional: dns5.name-services.com 3600 A 98.124.196.1