是否可以检查像 8.8.8.8 这样的名称服务器从我的名称服务器更新其记录之前还剩多少时间?
答案1
您可以使用dig
检查记录的 TTL - 如下所示:
; <<>> DiG 9.7.3 <<>> @8.8.8.8 www.serverfault.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3937
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;www.serverfault.com. IN A
;; ANSWER SECTION:
www.serverfault.com. 1800 IN CNAME serverfault.com.
serverfault.com. 1800 IN A 64.34.119.12
;; Query time: 88 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Thu Feb 23 23:15:23 2012
;; MSG SIZE rcvd: 67
具体来说,你需要注意答案中的值(在本例中为 1800)
;; ANSWER SECTION:
www.serverfault.com. 1800 IN CNAME serverfault.com.
serverfault.com. 1800 IN A 64.34.119.12
1800 是 TTL 到期前以及名称服务器 (8.8.8.8) 上刷新记录的秒数。
如果你运行该命令几次,你会看到 TTL 数字下降,因此截至撰写本文时,TTL 现在是这样(1659 秒)
;; ANSWER SECTION:
www.serverfault.com. 1659 IN CNAME serverfault.com.
serverfault.com. 1659 IN A 64.34.119.12
答案2
对于 Windows(本机),您可以使用nslookup
。
C:\>nslookup -debug www.serverfault.com 8.8.8.8
Got answer:
HEADER:
opcode = QUERY, id = 4, rcode = NOERROR
header flags: response, want recursion, recursion avail.
questions = 1, answers = 2, authority records = 0, additional = 0
QUESTIONS:
www.serverfault.com, type = A, class = IN
ANSWERS:
-> www.serverfault.com
canonical name = serverfault.com
ttl = 1791 (29 mins 51 secs)**
-> serverfault.com
internet address = 64.34.119.12
ttl = 1791 (29 mins 51 secs)**