Centos7 Restart Nic failed

Today, the CentOS 7 Network service cannot be restarted.

Now the various solutions to summarize, hoping to let the back of the classmate less walk a little fruitless ...

First look at the problem: The following error occurred after executing the service network restart command:

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. Failed
The following error message appears when prompted to enter the Systemctl status Network.service command:
Network.service-lsb:bring Up/down Networking
Loaded:loaded (/etc/rc.d/init.d/network; bad; vendor preset:disabled)
Active:failed (Result:exit-code) since five 2017-07-14 19:01:47 CST; 1min 16s ago
Docs:man:systemd-sysv-generator (8)
process:4681 execstart=/etc/rc.d/init.d/network Start (code=exited, Status=1/failure)
CGroup:/system.slice/network.service
└─1192/sbin/dhclient-h mini1-1-q-lf/var/lib/dhclient/dhclient--ens33.lease-pf/v ...
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 network[4681]: Rtnetlink answers:file exists
July 19:01:47 mini1 systemd[1]: Network.service:control process exited, code=exited Status=1
July 19:01:47 mini1 systemd[1]: Failed to start lsb:bring up/down networking.
July 19:01:47 mini1 systemd[1]: Unit Network.service entered failed state.
July 19:01:47 mini1 systemd[1]: Network.service failed.
The network service will not start first to ensure that the ifcfg-xxx in the/etc/sysconfig/network-scripts directory (each machine is not necessarily the same) without errors (if you have changed), here the error refers to the change process because the hand mistakenly hit the wrong letter.
Some of the most common practices on the Web are as follows:

1. And NetworkManager Service has conflict, this good solution, directly shut down the Networkmanger service is OK, services NetworkManager stop, and prohibit boot boot chkconfig NetworkManager Off. After that, it's good to restart.

2 and the configuration file MAC address does not match, this solves, uses the IP addr (or ifconfig) to view the MAC address

[[email protected] royfans]# IP a
1:lo: <LOOPBACK,UP,LOWER_UP> MTU 65536 qdisc noqueue State UNKNOWN Qle N 1
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 Pre Ferred_lft Forever
Inet6:: 1/128 scope host
Valid_lft forever Preferred_lft Forever
2:ens33: <broadcast,mu Lticast> MTU Qdisc NoOp State down Qlen
Link/ether 00:0c:29:5f:9e:1d brd ff:ff:ff:ff:ff:ff
3:virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> MTU Qdisc noqueue State qlen
Link/ether 52:54:00:67:8e:c3 BR D ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 BRD 192.168.122.255 scope global virbr0
Valid_lft Forever Preferred_lft Forever
4:virbr0-nic: <BROADCAST,MULTICAST> MTU qdisc pfifo_fast Master virbr0 State down Qlen
Li Nk/ether 52:54:00:67:8E:C3 BRD ff:ff:ff:ff:ff:ff

00:0C:29:5F:9E:1D This is the MAC address, the/etc/sysconfig/network-scripts/ifcfg-xxx in the hwaddr (if not added) to this MAC address

3. Set boot start a service named Networkmanager-wait-online, the command is:
Systemctl Enable Networkmanager-wait-online.service

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The above two are the solutions I have seen the most, but unfortunately, I have not solved it.

Have a look at the data, found the following methods:

4. Check the/etc/sysconfig/network-scripts, the remaining unrelated network card location files are all deleted, to avoid unnecessary impact, that is, only one file with Ifcfg beginning

5. Comment out the device line in the Ifcfg-xxx file.

6. Change the name in ifcfg-xxx to match the file name.

Centos7 Restart Nic failed