今天在开发的同事来说，内网不能通过域名访问自己的服务器!然后做了下面的测试发现这样的问题：
[root@itmop ~]# ping www.downcc.com
ping: unknown host www.downcc.com
[root@itmop ~]#ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=0.537 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=0.430 ms
— 192.168.1.1 ping statistics —
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.430/0.483/0.537/0.057 ms
[root@itmop ~]#cat /etc/host.conf
order bind,hosts
经过一翻查找后解决了，原因和方法如下：
[root@itmop ~]# grep host /etc/nsswitch.conf
#hosts: db files nisplus nis dns
hosts: files
主机只找文件不走dns，将其该成hosts: files dns 即可!