DNS/unbound/harden-referral-path/sampleについて、ここに記述してください。
ubuntu 14.04 にのせた unbound (1.4.22?)で
$ dig -t ns vv.qmail.jp ; <<>> DiG 9.9.5-3ubuntu0.1-Ubuntu <<>> -t ns vv.qmail.jp ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13737 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 2 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;vv.qmail.jp. IN NS ;; ANSWER SECTION: vv.qmail.jp. 345600 IN NS a.ns.vv.qmail.jp. ;; ADDITIONAL SECTION: a.ns.vv.qmail.jp. 345600 IN A 14.192.44.29 ;; Query time: 331 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Thu Dec 18 08:49:03 JST 2014 ;; MSG SIZE rcvd: 75
1. off 時
Dec 18 08:49:02 tmaeno unbound: [1062:0] info: resolving vv.qmail.jp. NS IN Dec 18 08:49:02 tmaeno unbound: [1062:0] info: response for vv.qmail.jp. NS IN Dec 18 08:49:02 tmaeno unbound: [1062:0] info: reply from <jp.> 156.154.100.5#53 Dec 18 08:49:02 tmaeno unbound: [1062:0] info: query response was REFERRAL Dec 18 08:49:02 tmaeno unbound: [1062:0] info: response for vv.qmail.jp. NS IN Dec 18 08:49:02 tmaeno unbound: [1062:0] info: reply from <qmail.jp.> 14.192.44.5#53 Dec 18 08:49:02 tmaeno unbound: [1062:0] info: query response was REFERRAL Dec 18 08:49:03 tmaeno unbound: [1062:0] info: response for vv.qmail.jp. NS IN Dec 18 08:49:03 tmaeno unbound: [1062:0] info: reply from <vv.qmail.jp.> 14.192.44.29#53 Dec 18 08:49:03 tmaeno unbound: [1062:0] info: query response was ANSWER
2. on
server: verbosity: 2 harden-referral-path: yes do-ip6: no do-udp: yes cache-min-ttl: 1800 # tcp-upstream: yes