在CentOS 7的安装过程中如果有选择相关虚拟化的的服务安装系统后，启动网卡时会发现有一个以网桥连接的私网地址的virbr0网卡，这个是因为在虚拟化中有使用到libvirtd服务生成的，如果不需要可以关闭后去掉：

一、查看IP及网桥设备

[root@etc ~]# ifconfig //查看IP地址

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1

inet 127.0.0.1/8 scope host lo

valid_lft forever preferred_lft forever

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

inet 192.168.133.121/24 brd 192.168.133.255 scope global ens33

valid_lft forever preferred_lft forever

3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN qlen 1000

inet 192.168.120.1/24 brd 192.168.120.255 scope global virbr0

valid_lft forever preferred_lft forever

[root@etc ~]# brctl show //查看网桥

bridge name bridge id STP enabled interfaces

virbr0 8321.5254115cdv00 yes virbr0-nic

[root@etc ~]#

二、删除网桥

[root@etc ~]# ifconfig virbr0 down

[root@etc ~]# brctl delbr virbr0 //删除网桥

三、禁用开机服务

[root@etc ~]# systemctl disable libvirtd.service //禁用libvirtd服务开机自启动

Removed symlink /etc/systemd/system/multi-user.target.wants/libvirtd.service.

Removed symlink /etc/systemd/system/sockets.target.wants/virtlockd.socket.

Removed symlink /etc/systemd/system/sockets.target.wants/virtlogd.socket.

[root@etc ~]# systemctl mask libvirtd.service

Created symlink from /etc/systemd/system/libvirtd.service to /dev/null.

再次使用ifconfig查看，即可发现virbr0不在了

[root@Node1 ~]# ifconfig

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1

inet 127.0.0.1/8 scope host lo

valid_lft forever preferred_lft forever

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000

inet 192.168.133.121/24 brd 192.168.133.255 scope global ens33

valid_lft forever preferred_lft forever

当然也可直接将libvirtd服务卸载，这样也就不会生成虚拟网卡，更是一劳永逸，待需要使用时，再安装该服务即可。操作命令如下：

yum remove libvirt-libs.x86_64