1、执行 service network restart 出现以下错误
Restarting network (via systemctl):  Job for network.service failed. See 'systemctl status network.service' and 'journalctl -xn' for details.
2、根据上面的提示，执行“systemctl status network.service”输出以下的类似信息：
[root@localhost ~]# systemctl status network.service
network.service - LSB: Bring up/down networking
   Loaded: loaded (/etc/rc.d/init.d/network)
   Active: failed (Result: exit-code) since 三 2014-11-05 15:30:10 CST; 1min 5s ago
 
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain network[2920]: RTNETLINK answers: File exists
11月 05 15:30:10 localhost.localdomain systemd[1]: network.service: control process exited, code=exited status=1
11月 05 15:30:10 localhost.localdomain systemd[1]: Failed to start LSB: Bring up/down networking.
11月 05 15:30:10 localhost.localdomain systemd[1]: Unit network.service entered failed state.
3、解决的办法（由于centos7中没有70-persistent-net.rules这个文件，复制出来的虚拟机(vmware）需要修改mac地址），就是修改mac地址。
 
4、如何查看centos7复制出来的虚拟机的mac地址，需要执行 “ip addr”，输出如下的类似信息：
[root@localhost ~]# ip addr
1: lo:
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno16777736:
    link/ether 00:0f:19:10:12:f1 brd ff:ff:ff:ff:ff:ff
    inet 192.168.38.135/24 brd 192.168.38.255 scope global dynamic eno16777736
       valid_lft 1681sec preferred_lft 1681sec
    inet6 fe80::20c:11aa:ae11:4fe4/64 scope link
       valid_lft forever preferred_lft forever
 
注意上面加粗加红的字，这就是新的mac地址。
接下来就剩下修改ifcfg-XXX文件了，只修改HWADDR就可以了。接下来执行service network restart 就正常了。


《二》
如果还是启动失败    查看是否有如下错误信息
Nov 23 22:09:07 hdcoe02 network[597]: Bringing up loopback interface:  Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'   
Nov 23 22:09:07 hdcoe02 network[597]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'  
Nov 23 22:09:08 hdcoe02 network[597]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'  
Nov 23 22:09:08 hdcoe02 network[597]: Could not load file '/etc/sysconfig/network-scripts/ifcfg-lo'  Nov 23 22:09:08 hdcoe02 network[597]: [  OK  ]  
Nov 23 22:09:08 hdcoe02 network[597]: Bringing up interface enp0s25:  Error: Connection activation failed: Connection 'enp0s25' is not available on the device enp0s25 at this time.  
设定开机启动一个名为NetworkManager-wait-online服务，命令为：
systemctl enable NetworkManager-wait-online.service
《三》
我也是上面方法都测试完了 一直不成功，最后发现时因为在VMware 虚拟机里面的系统  右上角显示的连接都没有连接上，虽然报错都一样，最后我在虚拟机设置里面将原来的网络适配器删掉，重新建了一个新的网络适配器，这次进去，显示连接成功，再用上面的方法，问题解决。

《四》

[vmware workstation ]Failed to start LSB: Bring up/down networking

辛辛苦苦安装了虚拟机，辛辛苦苦安装Fedora/CentOS,某次重启后丫的爆出这么玩意，

11月 05 15:30:10 localhost.localdomain systemd[1]: network.service: control process exited, code=exited status=1

11月 05 15:30:10 localhost.localdomain systemd[1]: Failed to start LSB: Bring up/down networking.

从此SSH不能使用，samba不能使用，高了多少个日夜都没浓度哦啊

但这不是你配置的问题，是虚拟机傻了