今天发现服务器ping，baidu都要好长时间，多加了几个dns server就ok，但不同的dns的响应时间不尽相同。
最终，/etc/resolv.conf的结果如下：
nameserver 114.114.114.114
nameserver 119.97.175.154
nameserver 8.8.8.8
nameserver 202.96.128.86
下面是测试结果：
1、114.114.114.114：
[root@ fufangchun]# ping 114.114.114.114
PING 114.114.114.114 (114.114.114.114) 56(84) bytes of data.
64 bytes from 114.114.114.114: icmp_seq=1 ttl=65 time=7.39 ms
64 bytes from 114.114.114.114: icmp_seq=2 ttl=61 time=7.27 ms
^C
--- 114.114.114.114 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1548ms
rtt min/avg/max/mdev = 7.277/7.336/7.396/0.104 ms
2、119.97.175.154：
湖北的。
[root@ fufangchun]# ping 119.97.175.154
PING 119.97.175.154 (119.97.175.154) 56(84) bytes of data.
64 bytes from 119.97.175.154: icmp_seq=1 ttl=52 time=16.5 ms
^C
--- 119.97.175.154 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 792ms
rtt min/avg/max/mdev = 16.529/16.529/16.529/0.000 ms
3、8.8.8.8：
[root@ fufangchun]# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=3 ttl=43 time=159 ms
^C
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 1 received, 66% packet loss, time 2971ms
rtt min/avg/max/mdev = 159.999/159.999/159.999/0.000 ms
4、202.96.128.86：
广东的。
[root@ fufangchun]# ping 202.96.128.86
PING 202.96.128.86 (202.96.128.86) 56(84) bytes of data.
^C
--- 202.96.128.86 ping statistics ---
24 packets transmitted, 0 received, 100% packet loss, time 23602ms