UDP 53: 일반적인 DNS 질의 및 응답
TCP 53: zone transfer와 같이 많은 용량을 전송할 때
UDP 53의 메시지 사이즈가 484 byte를 초과할 때 TCP로 재질의
<UDP를 이용한 DNS 질의>
[root@jo:~]#dig @ns.cho.iss www.cho.iss. any +novc [root@jo:~]#dig @ns.cho.iss www.cho.iss. any +notcp
; <<>> DiG 9.3.4-P1 <<>> @ns.cho.iss www.cho.iss. any +notcp ; (1 server found) ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53597 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; QUESTION SECTION: ;www.cho.iss. IN ANY
;; ANSWER SECTION: www.cho.iss. 86400 IN A 192.168.100.100
;; AUTHORITY SECTION: cho.iss. 86400 IN NS ns.cho.iss.
;; ADDITIONAL SECTION: ns.cho.iss. 86400 IN A 192.168.100.1
;; Query time: 0 msec ;; SERVER: 192.168.100.1#53(192.168.100.1) ;; WHEN: Wed Oct 28 11:17:02 2009 ;; MSG SIZE rcvd: 78 |
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<TCP를 이용한 DNS 질의>
[root@jo:~]#dig @ns.cho.iss www.cho.iss. any +vc [root@jo:~]#dig @ns.cho.iss www.cho.iss. any +tcp
; <<>> DiG 9.3.4-P1 <<>> @ns.cho.iss www.cho.iss. any +tcp ; (1 server found) ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26578 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1
;; QUESTION SECTION: ;www.cho.iss. IN ANY
;; ANSWER SECTION: www.cho.iss. 86400 IN A 192.168.100.100
;; AUTHORITY SECTION: cho.iss. 86400 IN NS ns.cho.iss.
;; ADDITIONAL SECTION: ns.cho.iss. 86400 IN A 192.168.100.1
;; Query time: 3 msec ;; SERVER: 192.168.100.1#53(192.168.100.1) ;; WHEN: Wed Oct 28 11:17:05 2009 ;; MSG SIZE rcvd: 78 |
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