例如,/ etc /中的resolv.conf如下所示: -
search example.com nameserver 172.16.1.254 nameserver 172.16.2.254 options timeout:3 options attempts:2
这里,超时3表示3秒.但是,超时值的意义是什么?是连接到DNS服务器所需的时间吗?或者是否允许等待DNS服务器返回URL的IP地址值?
确切地说,Timeout值是从主机名通过DNS服务器解析IP地址的时间,超时选项是减少主机名查找时间
timeout:n sets the amount of time the resolver will wait for a response from a remote name server before retrying the query via a different name server. Measured in seconds, the default is RES_TIMEOUT (currently 5, see <resolv.h>). The value for this option is silently capped to 30.
有关更多信息,请参阅http://man7.org/linux/man-pages/man5/resolver.5.html