CentOS7开机或断网后无法自动连接网络

network与NetworkManager其它是相辅相成的作用，只需要使用其中一种方式来管理即可，另外一种可以禁用掉

`查看NetworkManager的是否为自启动

systemctl list-unit-files --type service | grep NetworkManager
`

如果不是enabled则将其设置为enabled.

其他网络设置值常用命令：
`临时关闭
systemctl stop NetworkManager
永久关闭
systemctl disable NetworkManager
重启
systemctl restart network

禁止开机启动
chkconfig NetworkManager off
开机等待
systemctl enable NetworkManager-wait-online.service

查看是否开机启动：systemctl is-enabled NetworkManager

开机启动：systemctl enable NetworkManager

systemctl restart network`