DNS resolve 해보기.

 

 

naver.com의 IP는 nslookup을 통해 알수 있다.

kkeunuk@kkeunukD6W96 ~ % nslookup naver.com Server: 10.217.194.19 Address: 10.217.194.19#53 Non-authoritative answer: Name: naver.com Address: 223.130.195.200 Name: naver.com Address: 223.130.200.104 Name: naver.com Address: 223.130.195.95 Name: naver.com Address: 223.130.200.107

 

 

full resolver가 권한있는 DNS 서버에 질의하여 얻는 과정을 확인해보았다.

TLD부터 2nd, 3rd domain 까지 확인 방법

 

1. 먼저 full resolver가 TLD 로 쿼리

198.41.0.4는 TLD  root domain name server 중 A root server이고, naver.com에 대한 A 리소스리코드에 대한 질의를 함.

질의 받은 A root DNS 는 .com에 대해 위임처에 위임함. (a~m.gtld-servers.net.)

a~m.gtld-servers.net에 해당 되는 IP address는 additional section에서 확인할수 있다.

kkeunuk@kkeunukD6W96 ~ % dig +norec @198.41.0.4 naver.com A ; <<>> DiG 9.10.6 <<>> +norec @198.41.0.4 naver.com A ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 33015 ;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 13, ADDITIONAL: 27 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;naver.com. IN A ;; AUTHORITY SECTION: com. 172800 IN NS e.gtld-servers.net. com. 172800 IN NS b.gtld-servers.net. com. 172800 IN NS j.gtld-servers.net. com. 172800 IN NS m.gtld-servers.net. com. 172800 IN NS i.gtld-servers.net. com. 172800 IN NS f.gtld-servers.net. com. 172800 IN NS a.gtld-servers.net. com. 172800 IN NS g.gtld-servers.net. com. 172800 IN NS h.gtld-servers.net. com. 172800 IN NS l.gtld-servers.net. com. 172800 IN NS k.gtld-servers.net. com. 172800 IN NS c.gtld-servers.net. com. 172800 IN NS d.gtld-servers.net. ;; ADDITIONAL SECTION: e.gtld-servers.net. 172800 IN A 192.12.94.30 e.gtld-servers.net. 172800 IN AAAA 2001:502:1ca1::30 b.gtld-servers.net. 172800 IN A 192.33.14.30 b.gtld-servers.net. 172800 IN AAAA 2001:503:231d::2:30 j.gtld-servers.net. 172800 IN A 192.48.79.30 j.gtld-servers.net. 172800 IN AAAA 2001:502:7094::30 m.gtld-servers.net. 172800 IN A 192.55.83.30 m.gtld-servers.net. 172800 IN AAAA 2001:501:b1f9::30 i.gtld-servers.net. 172800 IN A 192.43.172.30 i.gtld-servers.net. 172800 IN AAAA 2001:503:39c1::30 f.gtld-servers.net. 172800 IN A 192.35.51.30 f.gtld-servers.net. 172800 IN AAAA 2001:503:d414::30 a.gtld-servers.net. 172800 IN A 192.5.6.30 a.gtld-servers.net. 172800 IN AAAA 2001:503:a83e::2:30 g.gtld-servers.net. 172800 IN A 192.42.93.30 g.gtld-servers.net. 172800 IN AAAA 2001:503:eea3::30 h.gtld-servers.net. 172800 IN A 192.54.112.30 h.gtld-servers.net. 172800 IN AAAA 2001:502:8cc::30 l.gtld-servers.net. 172800 IN A 192.41.162.30 l.gtld-servers.net. 172800 IN AAAA 2001:500:d937::30 k.gtld-servers.net. 172800 IN A 192.52.178.30 k.gtld-servers.net. 172800 IN AAAA 2001:503:d2d::30 c.gtld-servers.net. 172800 IN A 192.26.92.30 c.gtld-servers.net. 172800 IN AAAA 2001:503:83eb::30 d.gtld-servers.net. 172800 IN A 192.31.80.30 d.gtld-servers.net. 172800 IN AAAA 2001:500:856e::30 ;; Query time: 103 msec ;; SERVER: 198.41.0.4#53(198.41.0.4) ;; WHEN: Wed Nov 15 13:49:31 KST 2023 ;; MSG SIZE  rcvd: 834

 

 

2. full resolver로 .com DNS에  naver.com A 리소스레코드 쿼리를 하였다.

naver.com에 대해서 ns1~2.naver.com DNS 서버로 위임을 하였고, 

마찬가지로 ns1~2.naver.com에 대한 IP는 additional secition에서 확인할수 있다.

kkeunuk@kkeunukD6W96 ~ % dig +norec @192.12.94.30 naver.com A ; <<>> DiG 9.10.6 <<>> +norec @192.12.94.30 naver.com A ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43172 ;; flags: qr; QUERY: 1, ANSWER: 0, AUTHORITY: 2, ADDITIONAL: 3 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;naver.com. IN A ;; AUTHORITY SECTION: naver.com. 172800 IN NS ns2.naver.com. naver.com. 172800 IN NS ns1.naver.com. ;; ADDITIONAL SECTION: ns2.naver.com. 172800 IN A 125.209.249.6 ns1.naver.com. 172800 IN A 125.209.248.6 ;; Query time: 128 msec ;; SERVER: 192.12.94.30#53(192.12.94.30) ;; WHEN: Wed Nov 15 13:52:22 KST 2023 ;; MSG SIZE  rcvd: 106

 

 

3. naver.com의 IP를 알아내기위해 마지막으로 full resolver로 ns1.naver.com으로 쿼리를 날려보았다. 

flag 에 aa 마크가 보인다는건, 해당 서버에서는 A 리소스리코드에 대해 답이 있다는 표시이기도 하다. 

question에 naver.com이 있고, answer section에는 naver.com의 A리소스리코드가 있다. 

naver.com은 4개의 IP를 가지고 있다.

kkeunuk@kkeunukD6W96 ~ % dig +norec @125.209.249.6 naver.com A ; <<>> DiG 9.10.6 <<>> +norec @125.209.249.6 naver.com A ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21295 ;; flags: qr aa; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 1232 ;; QUESTION SECTION: ;naver.com. IN A ;; ANSWER SECTION: naver.com. 300 IN A 223.130.195.95 naver.com. 300 IN A 223.130.195.200 naver.com. 300 IN A 223.130.200.107 naver.com. 300 IN A 223.130.200.104