나는 이것이 더 철학적인 질문이라고 생각한다.
기록은 바뀌었지만 dig
새로운 것만 보이는 것 같습니다. ssh
/ ping
등은 이전 주소를 사용합니다.
표시된 레코드의 TTL dig
도 올바르게 표시됩니다.
이것은 실제로 다른 네임서버 응답입니까, 아니면 단지 숨겨진 DNS 캐시입니까?
$ host -v boing
Trying "boing"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7276
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;boing. IN A
;; ANSWER SECTION:
boing. 1213 IN CNAME ec2-52-209-211-218.eu-west-1.compute.amazonaws.com.
ec2-52-209-211-218.eu-west-1.compute.amazonaws.com. 514066 IN A 52.209.211.218
Received 112 bytes from 192.168.0.1#53 in 1 ms
하지만:
$ dig @192.168.0.1 boing
; <<>> DiG 9.10.4-P2 <<>> @192.168.0.1 boing
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 34806
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;boing. IN A
;; ANSWER SECTION:
boing. 3441 IN CNAME ec2-52-211-117-189.eu-west-1.compute.amazonaws.com.
ec2-52-211-117-189.eu-west-1.compute.amazonaws.com. 604641 IN A 52.211.117.189
;; Query time: 1 msec
;; SERVER: 192.168.0.1#53(192.168.0.1)
;; WHEN: Sat Sep 24 12:08:50 CEST 2016
;; MSG SIZE rcvd: 123