问题现象：

[root@decode from_jackzhang]# ping ping: unknown host

分析问题：

dns没有配置

解决问题：

配置dns为:8.8.8.8

[root@decode from_jackzhang]# setup[root@decode from_jackzhang]# ping PING www. (119.75.217.109) 56(84) bytes of data.64 bytes from 119.75.217.109: icmp_seq=1 ttl=54 time=31.7 ms64 bytes from 119.75.217.109: icmp_seq=2 ttl=54 time=32.1 ms64 bytes from 119.75.217.109: icmp_seq=3 ttl=54 time=31.5 ms^C--- www. ping statistics ---3 packets transmitted, 3 received, 0% packet loss, time 2718msrtt min/avg/max/mdev = 31.556/31.839/32.166/0.290 ms[root@decode from_jackzhang]#