在执行 yum install gcc 时 发现下载失败

ping www.baidu.com

ping 不通

ping 百度的IP：220.181.111.188却能ping 通

由此证明是DNS的问题

百度后查到设置DNS 需要运行命令：vi /etc/resolv.conf

添加：

nameserver 192.168.0.1

nameserver 192.168.0.1

然而运行vi /etc/resolv.conf后提示：

# Generated by NetworkManager
search An

# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com

于是运行 vi /etc/sysconfig/network-scripts/ifcfg-eth0

添加

# DNS1=192.168.0.1
# DNS2=192.168.0.1
# DOMAIN=lab.foo.com bar.foo.com    

运行service network restart

 发现还是ping 不通

运行         vi /etc/resolv.conf 发现添加的nameserver 丢失

网络搜索后找到解决方案：

1、#Remove network Manager from startup service

chkconfig NetworkManagerMangager off

2、#Add Default Net Manager

chconfig network on

3、Stop NetworkManager first

service NetworkManager stop

4、#and then start Default Manager

service network start

5、#restart network

service network restart

重新配置DNS配置文件 重启网络

ping www.baidu.com

成功

本文参考http://wenku.baidu.com/link?url=HdeBL7k6lihJId-zQwmIHw5mKswm4d7lS8P-YRHb7IgBpKYlRMXNVO5sFxgDS7BgwRN9v2iX5a5C9NbgMqQ0DTJPSH1CIb47_VqzxRdUhcW

Linux DNS 设置失败