三种方法解决 Failed to start LSB: Bring up/down networking 问题

《—》

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/ether00:0f: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。

原博文地址：http://blog.csdn.net/qq_21398167/article/details/46694179