准备重启网卡，用了两条命令都没能成功

[root@localhost Desktop]# ifup eth0
Active connection state: activating
Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/1
^C** Message: Caught signal 2, shutting down...
[root@localhost Desktop]# /etc/init.d/network restart
Shutting down interface eth0:  Device state: 3 (disconnected)
                                                           [  OK  ]
Shutting down loopback interface:                          [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface eth0:  Active connection state: activating
Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/2
state: activated
注意到两次的报错都是相同的一句话

Active connection path: /org/freedesktop/NetworkManager/ActiveConnection/

百度找寻解决办法，得到如下答案

通过网络管理工具修改IP之后，当前修改操作是不会生效的。那如何消除这个提示呢？

其实，问题的原因是RedHat自己开发的NetworkManager管理工具和/etc/sysconfig/network-scripts/ifcfg-ethx配置不同步造成的。如果要消除这个提示，请关闭NetworkManager服务即可：

[root@vdb1 dev]# chkconfig NetworkManager off  ----

只需要取消一个服务就可以了

[root@localhost Desktop]# service NetworkManager stop
Stopping NetworkManager daemon:                            [  OK  ]
接下来继续之前的步骤就可以了

[root@localhost Desktop]# /etc/init.d/network restart
Shutting down interface eth0:                              [  OK  ]
Shutting down loopback interface:                          [  OK  ]
Bringing up loopback interface:                            [  OK  ]
Bringing up interface eth0:  
Determining IP information for eth0... done.
                                                           [  OK  ]