DNS/KnotResolver/d.qmail.jp/2について、ここに記述してください。
$ kdig -t a a.b.c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 57800 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 0; AUTHORITY: 1; ADDITIONAL: 0 ;; QUESTION SECTION: ;; a.b.c.d.qmail.jp. IN A ;; AUTHORITY SECTION: a.b.c.d.qmail.jp. 2560 IN SOA a.ns.a.b.c.d.qmail.jp. hostmaster.a.b.c.d.qmail.jp. 1444734355 16384 2048 1048576 2560 ;; Received 86 B ;; Time 2015-10-24 17:03:57 JST ;; From 127.0.0.3@53(UDP) in 173.1 ms tmaeno@tmaeno:~$ kdig -t ns d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NXDOMAIN; id: 23681 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 0; AUTHORITY: 1; ADDITIONAL: 0 ;; QUESTION SECTION: ;; d.qmail.jp. IN NS ;; AUTHORITY SECTION: qmail.jp. 2550 IN SOA f.ns.qmail.jp. hostmaster.m.qmail.jp. 1445673818 16384 2048 1048576 2560 ;; Received 82 B ;; Time 2015-10-24 17:04:07 JST ;; From 127.0.0.3@53(UDP) in 0.2 ms tmaeno@tmaeno:~$ kdig -t txt c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 20845 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 0 ;; QUESTION SECTION: ;; c.d.qmail.jp. IN TXT ;; ANSWER SECTION: c.d.qmail.jp. 86400 IN TXT "c.d.qmail.jp" ;; Received 55 B ;; Time 2015-10-24 17:04:22 JST ;; From 127.0.0.3@53(UDP) in 79.7 ms tmaeno@tmaeno:~$ kdig -t a c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 33423 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 0; AUTHORITY: 1; ADDITIONAL: 0 ;; QUESTION SECTION: ;; c.d.qmail.jp. IN A ;; AUTHORITY SECTION: d.qmail.jp. 2560 IN SOA a.ns.d.qmail.jp. hostmaster.d.qmail.jp. 1445673893 16384 2048 1048576 2560 ;; Received 82 B ;; Time 2015-10-24 17:05:04 JST ;; From 127.0.0.3@53(UDP) in 64.0 ms tmaeno@tmaeno:~$ dnsq ns d.qmail.jp f.ns.qmail.jp 2 d.qmail.jp: 47 bytes, 1+1+0+0 records, response, authoritative, noerror query: 2 d.qmail.jp answer: d.qmail.jp 259200 NS a.ns.d.qmail.jp tmaeno@tmaeno:~$ dnsq a a.ns.d.qmail.jp f.ns.qmail.jp 1 a.ns.d.qmail.jp: 49 bytes, 1+1+0+0 records, response, authoritative, noerror query: 1 a.ns.d.qmail.jp answer: a.ns.d.qmail.jp 259200 A 14.192.44.29 tmaeno@tmaeno:~$ kdig -t a c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 46004 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 0; AUTHORITY: 1; ADDITIONAL: 0 ;; QUESTION SECTION: ;; c.d.qmail.jp. IN A ;; AUTHORITY SECTION: d.qmail.jp. 2451 IN SOA a.ns.d.qmail.jp. hostmaster.d.qmail.jp. 1445673893 16384 2048 1048576 2560 ;; Received 82 B ;; Time 2015-10-24 17:06:53 JST ;; From 127.0.0.3@53(UDP) in 0.3 ms tmaeno@tmaeno:~$ kdig -t txt c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 5935 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 0 ;; QUESTION SECTION: ;; c.d.qmail.jp. IN TXT ;; ANSWER SECTION: c.d.qmail.jp. 86225 IN TXT "c.d.qmail.jp" ;; Received 55 B ;; Time 2015-10-24 17:07:17 JST ;; From 127.0.0.3@53(UDP) in 0.2 ms tmaeno@tmaeno:~$ kdig -t txt b.c.d.qmail.jp @127.0.0.3 ;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 5851 ;; Flags: qr rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 0 ;; QUESTION SECTION: ;; b.c.d.qmail.jp. IN TXT ;; ANSWER SECTION: b.c.d.qmail.jp. 86400 IN TXT "b.c.d.qmail.jp" ;; Received 59 B ;; Time 2015-10-24 17:07:25 JST ;; From 127.0.0.3@53(UDP) in 58.8 ms