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