当在Linux机器上ping域名，提示

ping: www.baidu.com: Name or service not known

这说明绝大部分原因是由于dns服务器没有配置导致的问题。
DNS:
8.8.8.8 或者 114.114.114.114

1.可以直接在/ect/syconfig/network-scripts/ifcfg-xxx里面添加:
DNS1=8.8.8.8
DNS2=114.114.114.114
重启网络： service network restart
查看/etc/resolv.conf就会出现:

[root@localhost hadoop]# cat /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.8.6

2.在文件中添加如下两行：

nameserver 8.8.8.8
nameserver 8.8.4.4

保存退出，重启服务器。之后再ping 一次试一试
然后再ping 就成功了

[root@gateway-1 grafana]# ping www.baidu.com
PING www.a.shifen.com
(14.215.177.38) 56(84) bytes of data. 64 bytes from 14.215.177.38
(14.215.177.38): icmp_seq=1 ttl=53 time=6.92 ms 64 bytes from 14.215.177.38
(14.215.177.38): icmp_seq=2 ttl=53 time=6.19 ms 64 bytes from 14.215.177.38
(14.215.177.38): icmp_seq=3 ttl=53 time=6.22 ms 64
bytes from 14.215.177.38 (14.215.177.38): icmp_seq=4 ttl=53 time=6.35
ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=5 ttl=53
time=6.30 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=6 ttl=53 time=6.26 ms

参考：
https://cloud.tencent.com/developer/article/1137659