目前我的 ubuntu 17.10 上的 dns 缓存时间是 300 秒。
使用命令：
dig +ttlid copyleaks.com
给我：
; <<>> DiG 9.10.3-P4-Ubuntu <<>> +ttlid copyleaks.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19394
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;copyleaks.com. IN A
;; ANSWER SECTION:
copyleaks.com. 299 IN A 104.24.29.22
copyleaks.com. 299 IN A 104.24.28.22
;; Query time: …