*无法联网的明显表现会有: cannot find a valid baseurl for repo:base/7/x86_64 1.yum install出现 Error: cannot find a valid baseurl or repo:base 2.ping host会提示unknown host 方法一. 1.打开 vi /etc/sysconfig/network-scripts/ifcfg-eth0(每个机子都可能不一样,但格式会是“ifcfg-eth数字”),把ONBOOT…