www.jprs.co.jpのIPアドレスは？
ルートDNS
$ curl -i http://www.internic.net/domain/named.root
HTTP/1.1 200 OK
Date: Fri, 14 Mar 2025 00:51:06 GMT
Server: Apache
Last-Modified: Thu, 13 Mar 2025 20:32:00 GMT
Content-Length: 3311
ETag: "cef-6303f36c1b000"
Accept-Ranges: bytes
Cache-Control: max-age=420
Expires: Fri, 14 Mar 2025 00:56:12 GMT
X-Frame-Options: SAMEORIGIN
Referrer-Policy: origin-when-cross-origin
Content-Security-Policy: upgrade-insecure-requests
Age: 114
Content-Type: text/plain; charset=UTF-8
Content-Language: en
; This file holds the information on root name servers needed to
; initialize cache of Internet domain name servers
; (e.g. reference this file in the "cache . <file>"
; configuration file of BIND domain name servers).
;
; This file is made available by InterNIC
; under anonymous FTP as
; file /domain/named.cache
; on server FTP.INTERNIC.NET
; -OR- RS.INTERNIC.NET
;
; last update: March 13, 2025
; related version of root zone: 2025031301
;
; FORMERLY NS.INTERNIC.NET
;
. 3600000 NS A.ROOT-SERVERS.NET.
A.ROOT-SERVERS.NET. 3600000 A 198.41.0.4
A.ROOT-SERVERS.NET. 3600000 AAAA 2001:503:ba3e::2:30
;
; FORMERLY NS1.ISI.EDU
;
. 3600000 NS B.ROOT-SERVERS.NET.
B.ROOT-SERVERS.NET. 3600000 A 170.247.170.2
B.ROOT-SERVERS.NET. 3600000 AAAA 2801:1b8:10::b
;
; FORMERLY C.PSI.NET
;
. 3600000 NS C.ROOT-SERVERS.NET.
C.ROOT-SERVERS.NET. 3600000 A 192.33.4.12
C.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:2::c
;
; FORMERLY TERP.UMD.EDU
;
. 3600000 NS D.ROOT-SERVERS.NET.
D.ROOT-SERVERS.NET. 3600000 A 199.7.91.13
D.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:2d::d
;
; FORMERLY NS.NASA.GOV
;
. 3600000 NS E.ROOT-SERVERS.NET.
E.ROOT-SERVERS.NET. 3600000 A 192.203.230.10
E.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:a8::e
;
; FORMERLY NS.ISC.ORG
;
. 3600000 NS F.ROOT-SERVERS.NET.
F.ROOT-SERVERS.NET. 3600000 A 192.5.5.241
F.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:2f::f
;
; FORMERLY NS.NIC.DDN.MIL
;
. 3600000 NS G.ROOT-SERVERS.NET.
G.ROOT-SERVERS.NET. 3600000 A 192.112.36.4
G.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:12::d0d
;
; FORMERLY AOS.ARL.ARMY.MIL
;
. 3600000 NS H.ROOT-SERVERS.NET.
H.ROOT-SERVERS.NET. 3600000 A 198.97.190.53
H.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:1::53
;
; FORMERLY NIC.NORDU.NET
;
. 3600000 NS I.ROOT-SERVERS.NET.
I.ROOT-SERVERS.NET. 3600000 A 192.36.148.17
I.ROOT-SERVERS.NET. 3600000 AAAA 2001:7fe::53
;
; OPERATED BY VERISIGN, INC.
;
. 3600000 NS J.ROOT-SERVERS.NET.
J.ROOT-SERVERS.NET. 3600000 A 192.58.128.30
J.ROOT-SERVERS.NET. 3600000 AAAA 2001:503:c27::2:30
;
; OPERATED BY RIPE NCC
;
. 3600000 NS K.ROOT-SERVERS.NET.
K.ROOT-SERVERS.NET. 3600000 A 193.0.14.129
K.ROOT-SERVERS.NET. 3600000 AAAA 2001:7fd::1
;
; OPERATED BY ICANN
;
. 3600000 NS L.ROOT-SERVERS.NET.
L.ROOT-SERVERS.NET. 3600000 A 199.7.83.42
L.ROOT-SERVERS.NET. 3600000 AAAA 2001:500:9f::42
;
; OPERATED BY WIDE
;
. 3600000 NS M.ROOT-SERVERS.NET.
M.ROOT-SERVERS.NET. 3600000 A 202.12.27.33
M.ROOT-SERVERS.NET. 3600000 AAAA 2001:dc3::35
; End of file
ルート権威サーバーにwww.jprs.co.jp を聞いてみる
+norecで再帰検索しないようにする
$ dig +norec @198.41.0.4 www.jprs.co.jp A
; <<>> DiG 9.20.2-1-Debian <<>> +norec @198.41.0.4 www.jprs.co.jp A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51759
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 8, ADDITIONAL: 16
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;www.jprs.co.jp. IN A
;; AUTHORITY SECTION:
jp. 172800 IN NS e.dns.jp.
jp. 172800 IN NS g.dns.jp.
jp. 172800 IN NS c.dns.jp.
jp. 172800 IN NS a.dns.jp.
jp. 172800 IN NS h.dns.jp.
jp. 172800 IN NS d.dns.jp.
jp. 172800 IN NS f.dns.jp.
jp. 172800 IN NS b.dns.jp.
;; ADDITIONAL SECTION:
e.dns.jp. 172800 IN A 192.50.43.53
e.dns.jp. 172800 IN AAAA 2001:200:c000::35
g.dns.jp. 172800 IN A 203.119.40.1
c.dns.jp. 172800 IN A 156.154.100.5
c.dns.jp. 172800 IN AAAA 2001:502:ad09::5
a.dns.jp. 172800 IN A 203.119.1.1
a.dns.jp. 172800 IN AAAA 2001:dc4::1
h.dns.jp. 172800 IN A 161.232.72.25
h.dns.jp. 172800 IN AAAA 2a01:8840:1bc::25
d.dns.jp. 172800 IN A 210.138.175.244
d.dns.jp. 172800 IN AAAA 2001:240::53
f.dns.jp. 172800 IN A 150.100.6.8
f.dns.jp. 172800 IN AAAA 2001:2f8:0:100::153
b.dns.jp. 172800 IN A 202.12.30.131
b.dns.jp. 172800 IN AAAA 2001:dc2::1
;; Query time: 119 msec
;; SERVER: 198.41.0.4#53(198.41.0.4) (UDP)
;; WHEN: Fri Mar 14 09:54:51 JST 2025
;; MSG SIZE rcvd: 499
jpの権威サーバのIPの一つが 192.50.43.53 とわかった。
jpの権威サーバーにwww.jprs.co.jp を聞いてみる
$ dig +norec @192.50.43.53 www.jprs.co.jp A
; <<>> DiG 9.20.2-1-Debian <<>> +norec @192.50.43.53 www.jprs.co.jp A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5689
;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 4, ADDITIONAL: 9
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;www.jprs.co.jp. IN A
;; AUTHORITY SECTION:
jprs.co.jp. 86400 IN NS ns1.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns2.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns3.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns4.jprs.co.jp.
;; ADDITIONAL SECTION:
ns1.jprs.co.jp. 86400 IN A 202.11.16.49
ns2.jprs.co.jp. 86400 IN A 202.11.16.59
ns3.jprs.co.jp. 86400 IN A 203.105.65.178
ns4.jprs.co.jp. 86400 IN A 203.105.65.181
ns1.jprs.co.jp. 86400 IN AAAA 2001:df0:8::a153
ns2.jprs.co.jp. 86400 IN AAAA 2001:df0:8::a253
ns3.jprs.co.jp. 86400 IN AAAA 2001:218:3001::a153
ns4.jprs.co.jp. 86400 IN AAAA 2001:218:3001::a253
;; Query time: 19 msec
;; SERVER: 192.50.43.53#53(192.50.43.53) (UDP)
;; WHEN: Fri Mar 14 10:07:38 JST 2025
;; MSG SIZE rcvd: 291
co.jpは飛び越えて、jprs.co.jpの権威サーバの情報が得られた
jprs.co.jpの権威サーバにwww.jprs.co.jp を聞いてみる
$ dig +norec @202.11.16.49 www.jprs.co.jp A
; <<>> DiG 9.20.2-1-Debian <<>> +norec @202.11.16.49 www.jprs.co.jp A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33589
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 9
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;www.jprs.co.jp. IN A
;; ANSWER SECTION:
www.jprs.co.jp. 300 IN A 117.104.133.165
;; AUTHORITY SECTION:
jprs.co.jp. 86400 IN NS ns2.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns3.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns4.jprs.co.jp.
jprs.co.jp. 86400 IN NS ns1.jprs.co.jp.
;; ADDITIONAL SECTION:
ns1.jprs.co.jp. 86400 IN A 202.11.16.49
ns2.jprs.co.jp. 86400 IN A 202.11.16.59
ns3.jprs.co.jp. 86400 IN A 203.105.65.178
ns4.jprs.co.jp. 86400 IN A 203.105.65.181
ns1.jprs.co.jp. 86400 IN AAAA 2001:df0:8::a153
ns2.jprs.co.jp. 86400 IN AAAA 2001:df0:8::a253
ns3.jprs.co.jp. 86400 IN AAAA 2001:218:3001::a153
ns4.jprs.co.jp. 86400 IN AAAA 2001:218:3001::a253
;; Query time: 29 msec
;; SERVER: 202.11.16.49#53(202.11.16.49) (UDP)
;; WHEN: Fri Mar 14 10:11:38 JST 2025
;; MSG SIZE rcvd: 307
117.104.133.165とわかった。
再帰検索有無の違い
リゾルバに 8.8.8.8 （Google）を指定
再帰検索なし
$ dig +norec @8.8.8.8 www.jprs.co.jp A
; <<>> DiG 9.20.2-1-Debian <<>> +norec @8.8.8.8 www.jprs.co.jp A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 34082
;; flags: qr ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.jprs.co.jp. IN A
;; Query time: 19 msec
;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP)
;; WHEN: Fri Mar 14 10:02:21 JST 2025
;; MSG SIZE rcvd: 43
予想通り、結果が得られない。
再帰検索あり
$ dig @8.8.8.8 www.jprs.co.jp A
; <<>> DiG 9.20.2-1-Debian <<>> @8.8.8.8 www.jprs.co.jp A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40279
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.jprs.co.jp. IN A
;; ANSWER SECTION:
www.jprs.co.jp. 300 IN A 117.104.133.165
;; Query time: 30 msec
;; SERVER: 8.8.8.8#53(8.8.8.8) (UDP)
;; WHEN: Fri Mar 14 10:05:40 JST 2025
;; MSG SIZE rcvd: 59