最近在CentOS7中经常碰到虚拟机连不上网的问题，错误代码如下。
Restarting network (via systemctl): Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.[失败]使用systemctl status network.service命令查看结果如下：network.service - LSB: Bring up/down networkingLoaded: loaded (/etc/rc.d/init.d/network)Active: failed (Result: exit-code) since 三 2016-08-17 11:34:36 CST; 54s agoDocs: man:systemd-sysv-generator(8)Process: 3847 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=1/FAILURE)8月 17 11:34:36 python.cn network[3847]: RTNETLINK answers: File exists8月 17 11:34:36 python.cn network[3847]: RTNETLINK answers: File exists8月 17 11:34:36 python.cn network[3847]: RTNETLINK answers: File exists8月 17 11:34:36 python.cn network[3847]: RTNETLINK answers: File exists8月 17 11:34:36 python.cn network[3847]: RTNETLINK answers: File exists8月 17