如何绕过缓存的服务器，从命令行直接查询权威DNS名称服务器？

Question

如何绕过缓存的服务器，从Linux和Mac命令行直接查询权威的DNS名称服务器？

如果想要立即验证权威服务器上新创建的DNS主机名，并且不想等待缓存的DNS服务器“更新”/expire TTL，这是很有帮助的。

Answer 1

使用dig，您可以自动完成此操作。

$ dig +trace www.google.com

; <<>> DiG 9.8.3-P1 <<>> +trace www.google.com
;; global options: +cmd
.           376983  IN  NS  c.root-servers.net.
.           376983  IN  NS  d.root-servers.net.
.           376983  IN  NS  l.root-servers.net.
.           376983  IN  NS  j.root-servers.net.
.           376983  IN  NS  f.root-servers.net.
.           376983  IN  NS  b.root-servers.net.
.           376983  IN  NS  i.root-servers.net.
.           376983  IN  NS  g.root-servers.net.
.           376983  IN  NS  a.root-servers.net.
.           376983  IN  NS  e.root-servers.net.
.           376983  IN  NS  k.root-servers.net.
.           376983  IN  NS  m.root-servers.net.
.           376983  IN  NS  h.root-servers.net.
;; Received 512 bytes from 172.16.0.1#53(172.16.0.1) in 2424 ms

com.            172800  IN  NS  a.gtld-servers.net.
com.            172800  IN  NS  l.gtld-servers.net.
com.            172800  IN  NS  i.gtld-servers.net.
com.            172800  IN  NS  k.gtld-servers.net.
com.            172800  IN  NS  g.gtld-servers.net.
com.            172800  IN  NS  m.gtld-servers.net.
com.            172800  IN  NS  f.gtld-servers.net.
com.            172800  IN  NS  h.gtld-servers.net.
com.            172800  IN  NS  e.gtld-servers.net.
com.            172800  IN  NS  j.gtld-servers.net.
com.            172800  IN  NS  d.gtld-servers.net.
com.            172800  IN  NS  c.gtld-servers.net.
com.            172800  IN  NS  b.gtld-servers.net.
;; Received 504 bytes from 192.36.148.17#53(192.36.148.17) in 4357 ms

google.com.     172800  IN  NS  ns2.google.com.
google.com.     172800  IN  NS  ns1.google.com.
google.com.     172800  IN  NS  ns3.google.com.
google.com.     172800  IN  NS  ns4.google.com.
;; Received 168 bytes from 192.33.14.30#53(192.33.14.30) in 503 ms

www.google.com.     300 IN  A   173.194.127.240
www.google.com.     300 IN  A   173.194.127.244
www.google.com.     300 IN  A   173.194.127.242
www.google.com.     300 IN  A   173.194.127.241
www.google.com.     300 IN  A   173.194.127.243
;; Received 112 bytes from 216.239.32.10#53(216.239.32.10) in 164 ms