1)ethtool -i eth0查看网卡驱动信息,如e1000
2)modprobe -r e1000
3)modprobe e1000
4)ifup eth0
如何显示:Connection activation failed: Device not managed by NetworkManager or unavailable
是由于network服务与NetworkManager服务冲突造成的
可以service NetworkManager stop
service network restart