[root@localhost ~]# cat /etc/resolv.conf
[root@localhost ~]#ping www.sina.com.cn
ping: unknown host www.sina.com.cn
添加nameserver
[root@localhost ~]# cat /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4
[root@localhost ~]# ping www.sina.com.cn
PING spool.grid.sinaedge.com (219.238.4.9) 56(84) bytes of data.
^C64 bytes from 219.238.4.9: icmp_seq=1 ttl=58 time=6.26 ms
--- spool.grid.sinaedge.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 6.264/6.264/6.264/0.000 ms
[root@localhost ~]# ping www.baidu.com
PING www.a.shifen.com (119.75.216.20) 56(84) bytes of data.
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=1 ttl=56 time=10.7 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=2 ttl=56 time=8.50 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=3 ttl=56 time=21.4 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=4 ttl=56 time=6.05 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=5 ttl=56 time=7.13 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=6 ttl=56 time=6.40 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=7 ttl=56 time=8.24 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=9 ttl=56 time=6.02 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=10 ttl=56 time=9.95 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=11 ttl=56 time=8.04 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=12 ttl=56 time=13.7 ms
64 bytes from 127.0.0.1 (119.75.216.20): icmp_seq=13 ttl=56 time=10.6 ms