重启网络服务时 Bringing up interface eth0

重启网络服务时报错：

　　 Bringing up interface eth0： Error:Connection activation failed:Device not managed by NetworkManager

1. Remove Network Manager from startup Services.
chkconfig NetworkManager off

2. Add Default Net Manager
chkconfig network on

3.Stop NetworkManager first
service NetworkManager stop

4.and then start Default Manager
service network start

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