我想这更多的是一个哲学问题。
记录已经改变，但dig似乎只看到了新的。ssh/ping等使用旧地址。
看到的记录的 TTLdig也正确滴答。
这真的是域名服务器响应不同还是只是隐藏的 DNS 缓存？
$ 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
然而：
$ 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