1. ルートゾーンKSK/日本では/dns-oarc.net


https://www.dns-oarc.net/oarc/services/replysizetest

$ dig +short rs.dns-oarc.net txt

/段階的検査

手元での結果

rst.x487.rs.dns-oarc.net.
rst.x461.x487.rs.dns-oarc.net.
rst.x466.x461.x487.rs.dns-oarc.net.
"39.110.135.12 sent EDNS buffer size 512"
"39.110.135.12 DNS reply size limit is at least 487"
"Tested at 2017-08-08 02:12:41 UTC"

2. TCPなら

$ dig +tcp rs.dns-oarc.net txt

; <<>> DiG 9.11.1-P3 <<>> +tcp rs.dns-oarc.net txt
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 59776
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;rs.dns-oarc.net.               IN      TXT

;; ANSWER SECTION:
rs.dns-oarc.net.        60      IN      CNAME   rst.x4048.rs.dns-oarc.net.
rst.x4048.rs.dns-oarc.net. 59   IN      CNAME   rst.x4058.x4048.rs.dns-oarc.net.
rst.x4058.x4048.rs.dns-oarc.net. 58 IN  CNAME   rst.x4064.x4058.x4048.rs.dns-oarc.net.
rst.x4064.x4058.x4048.rs.dns-oarc.net. 57 IN TXT "Tested at 2017-08-08 02:14:12 UTC"
rst.x4064.x4058.x4048.rs.dns-oarc.net. 57 IN TXT "39.110.135.12 sent EDNS buffer size 4096"
rst.x4064.x4058.x4048.rs.dns-oarc.net. 57 IN TXT "39.110.135.12 DNS reply size limit is at least 4064"

;; Query time: 2349 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Aug 08 11:14:12 JST 2017
;; MSG SIZE  rcvd: 279


直接問い合わせたときの返事だが、これをresolverがどう処理するかも問題だ。

3. リゾルバー

 dig +bufsize=4096 rs.dns-oarc.net txt

/8.8.8.8

4. おかしい

/rst.x4090.rs.dns-oarc.net がおかしい。-- ToshinoriMaeno 2017-07-25 13:56:32

default install のはずだが、結果は見てのお楽しみ。-- ToshinoriMaeno 2017-07-25 10:58:04

5. 問い合わせ

$ dig -t txt rs.dns-oarc.net @ns00.rs.dns-oarc.net

; <<>> DiG 9.11.1 <<>> -t txt rs.dns-oarc.net @ns00.rs.dns-oarc.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63078
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 106, ADDITIONAL: 107

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;rs.dns-oarc.net.               IN      TXT

;; ANSWER SECTION:
rs.dns-oarc.net.        60      IN      CNAME   rst.x4090.rs.dns-oarc.net.

;; AUTHORITY SECTION:
x4090.rs.dns-oarc.net.  60      IN      NS      ns00.x4090.rs.dns-oarc.net.
x4090.rs.dns-oarc.net.  60      IN      NS      ns01.x4090.rs.dns-oarc.net.
x4090.rs.dns-oarc.net.  60      IN      NS      ns02.x4090.rs.dns-oarc.net.
...
x4090.rs.dns-oarc.net.  60      IN      NS      ns103.x4090.rs.dns-oarc.net.
x4090.rs.dns-oarc.net.  60      IN      NS      ns104.x4090.rs.dns-oarc.net.
x4090.rs.dns-oarc.net.  60      IN      NS      ns105.x4090.rs.dns-oarc.net.

;; ADDITIONAL SECTION:
ns00.x4090.rs.dns-oarc.net. 60  IN      A       64.191.0.134
ns01.x4090.rs.dns-oarc.net. 60  IN      A       64.191.0.134
ns02.x4090.rs.dns-oarc.net. 60  IN      A       64.191.0.134
...
ns103.x4090.rs.dns-oarc.net. 60 IN      A       64.191.0.134
ns104.x4090.rs.dns-oarc.net. 60 IN      A       64.191.0.134
ns105.x4090.rs.dns-oarc.net. 60 IN      A       64.191.0.134

;; Query time: 180 msec
;; SERVER: 64.191.0.133#53(64.191.0.133)
;; WHEN: Tue Jul 25 19:26:43 JST 2017
;; MSG SIZE  rcvd: 4090