命令

service network restart

提示

Job for network.service failed because the control process exited with error code. See “systemctl status network.service” and “journalctl -xe” for details.

原因分析

使用journalctl -xe命令查看日志后的具体错误

-- Unit network.service has begun starting up.
Oct 07 22:30:54 localhost.localdomain network[3419]: Bringing up loopback interface: 
Oct 07 22:30:54 localhost.localdomain NetworkManager[572]: <info>  [1696743054.2665] 
Oct 07 22:30:54 localhost.localdomain network[3419]: Bringing up interface ens33:  Er
Oct 07 22:30:54 localhost.localdomain network[3419]: [FAILED]
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: Bringing up interface ens33:  Er
Oct 07 22:30:54 localhost.localdomain network[3419]: [FAILED]
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain network[3419]: RTNETLINK answers: File exists
Oct 07 22:30:54 localhost.localdomain systemd[1]: network.service: control process ex
Oct 07 22:30:54 localhost.localdomain systemd[1]: Failed to start LSB: Bring up/down 
-- Subject: Unit network.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit network.service has failed.
-- 
-

解决办法1

大部分情况是ens33配置文件的内容错误，比如少了一个引号、DNS写成了DSN、GATEWAY写成了GATAWAY、IP格式错误等等。
修改错误内容再次重启即可。
比如这个同学，末尾少写了一个引号"：

解决办法2

RTNETLINK answers: File exists
对于这个错误：
Error: Connection activation failed: No suitable device found for this connection (device lo not available because device is strictly unmanaged).

问题原因

/etc/init.d/network
/etc/init.d/NetworkManager这两个服务有冲突。
从根本上说是NetworkMaganager（NM）的带来的冲突，停用NetworkManager即可解决。重启即可。

解决办法：

停止一次：

service NetworkManager stop

永久停止

chkconfig NetworkManager off
chkconfig network on
service NetworkManager stop
service network start

参考资料：
RTNETLINK answers: File exists错误解决方法-CSDN博客