DNS/watch/netways.ne.jpについて、ここに記述してください。

$dnsq any netways.ne.jp a.dns.jp

255 netways.ne.jp:
133 bytes, 1+0+3+3 records, response, noerror
query: 255 netways.ne.jp
authority: netways.ne.jp 86400 NS ns2.netways.ne.jp
authority: netways.ne.jp 86400 NS ns3.netways.ne.jp
authority: netways.ne.jp 86400 NS ns1.netways.ne.jp
additional: ns1.netways.ne.jp 86400 A 210.143.100.6
additional: ns2.netways.ne.jp 86400 A 210.143.100.95
additional: ns3.netways.ne.jp 86400 A 112.78.193.243

%dnsq any netways.ne.jp 210.143.100.6

255 netways.ne.jp:
187 bytes, 1+4+0+3 records, response, authoritative, noerror
query: 255 netways.ne.jp
answer: netways.ne.jp 0 SOA ns1.netways.ne.jp domain.netways.co.jp 2010080201 10800 3600 604800 0
answer: netways.ne.jp 0 NS ns3.netways.ne.jp
answer: netways.ne.jp 0 NS ns1.netways.ne.jp
answer: netways.ne.jp 0 NS ns2.netways.ne.jp
additional: ns1.netways.ne.jp 0 A 210.143.100.6
additional: ns2.netways.ne.jp 0 A 210.143.100.95
additional: ns3.netways.ne.jp 0 A 112.78.193.243

DNS/TTLが0 を見てください。 ns2.netways.ne.jp の A レコードをdnscacheに問い合わせてみました。

$ dnsqr a ns2.netways.ne.jp
1 ns2.netways.ne.jp:
51 bytes, 1+1+0+0 records, response, noerror
query: 1 ns2.netways.ne.jp
answer: ns2.netways.ne.jp 85779 A 210.143.100.95

$ dnsqr a ns2.netways.ne.jp
1 ns2.netways.ne.jp:
51 bytes, 1+1+0+0 records, response, noerror
query: 1 ns2.netways.ne.jp
answer: ns2.netways.ne.jp 84825 A 210.143.100.95

1. unbound cache の場合

$ dnsqr ns netways.ne.jp

2 netways.ne.jp:
133 bytes, 1+3+0+3 records, response, noerror
query: 2 netways.ne.jp
answer: netways.ne.jp 0 NS ns2.netways.ne.jp
answer: netways.ne.jp 0 NS ns3.netways.ne.jp
answer: netways.ne.jp 0 NS ns1.netways.ne.jp
additional: ns1.netways.ne.jp 0 A 210.143.100.6
additional: ns2.netways.ne.jp 0 A 210.143.100.95
additional: ns3.netways.ne.jp 0 A 112.78.193.243

$ dnsqr a ns1.netways.ne.jp

1 ns1.netways.ne.jp:
133 bytes, 1+1+3+2 records, response, noerror
query: 1 ns1.netways.ne.jp
answer: ns1.netways.ne.jp 0 A 210.143.100.6
authority: netways.ne.jp 0 NS ns3.netways.ne.jp
authority: netways.ne.jp 0 NS ns1.netways.ne.jp
authority: netways.ne.jp 0 NS ns2.netways.ne.jp
additional: ns2.netways.ne.jp 0 A 210.143.100.95
additional: ns3.netways.ne.jp 0 A 112.78.193.243

こっちの方がRFCに忠実な実装だと思うが、TTL 0 の悪影響が大きい。

2. unbound cache log

May 25 15:54:28 u11 unbound: [983:0] debug: validator[module 0] operate: extstate:module_state_initial event:module_event_new
May 25 15:54:28 u11 unbound: [983:0] info: validator operate: query <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_state_initial event:module_event_pass
May 25 15:54:28 u11 unbound: [983:0] info: resolving <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: resolving (init part 2):  <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: resolving (init part 3):  <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: processQueryTargets: <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: sending query: <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] debug: sending to target: <jp.> 156.154.100.5#53
May 25 15:54:28 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68408 val=92699
May 25 15:54:28 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_wait_reply event:module_event_reply
May 25 15:54:28 u11 unbound: [983:0] info: iterator operate: query <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: response for <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: reply from <jp.> 156.154.100.5#53
May 25 15:54:28 u11 unbound: [983:0] info: query response was REFERRAL
May 25 15:54:28 u11 unbound: [983:0] info: processQueryTargets: <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: sending query: <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] debug: sending to target: <netways.ne.jp.> 112.78.193.243#53
May 25 15:54:28 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68408 val=92699
May 25 15:54:28 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_wait_reply event:module_event_reply
May 25 15:54:28 u11 unbound: [983:0] info: iterator operate: query <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: response for <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] info: reply from <netways.ne.jp.> 112.78.193.243#53
May 25 15:54:28 u11 unbound: [983:0] info: query response was ANSWER
May 25 15:54:28 u11 unbound: [983:0] info: finishing processing for <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] debug: validator[module 0] operate: extstate:module_wait_module event:module_event_moddone
May 25 15:54:28 u11 unbound: [983:0] info: validator operate: query <netways.ne.jp. ANY IN>
May 25 15:54:28 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68408 val=92699

May 25 15:56:00 u11 unbound: [983:0] info: validator operate: query <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_state_initial event:module_event_pass
May 25 15:56:00 u11 unbound: [983:0] info: resolving <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: resolving (init part 2):  <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: resolving (init part 3):  <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: processQueryTargets: <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: sending query: <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] debug: sending to target: <jp.> 156.154.100.5#53
May 25 15:56:00 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68408 val=92699
May 25 15:56:00 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_wait_reply event:module_event_reply
May 25 15:56:00 u11 unbound: [983:0] info: iterator operate: query <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: response for <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: reply from <jp.> 156.154.100.5#53
May 25 15:56:00 u11 unbound: [983:0] info: query response was REFERRAL
May 25 15:56:00 u11 unbound: [983:0] info: processQueryTargets: <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: sending query: <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] debug: sending to target: <netways.ne.jp.> 210.143.100.95#53
May 25 15:56:00 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68688 val=92699
May 25 15:56:00 u11 unbound: [983:0] debug: iterator[module 1] operate: extstate:module_wait_reply event:module_event_reply
May 25 15:56:00 u11 unbound: [983:0] info: iterator operate: query <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: response for <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] info: reply from <netways.ne.jp.> 210.143.100.95#53
May 25 15:56:00 u11 unbound: [983:0] info: query response was ANSWER
May 25 15:56:00 u11 unbound: [983:0] info: finishing processing for <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] debug: validator[module 0] operate: extstate:module_wait_module event:module_event_moddone
May 25 15:56:00 u11 unbound: [983:0] info: validator operate: query <netways.ne.jp. ANY IN>
May 25 15:56:00 u11 unbound: [983:0] debug: cache memory msg=149853 rrset=332140 infra=68688 val=92699