1.新建网卡配置文件 ifcfg-br0，ip为原网卡的IP

vi /etc/sysconfig/network-scripts/ifcfg-bro
TYPE=bridge
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
NAME=br0
DEVICE=br0
ONBOOT=yes

IPADDR=192.168.102.100
PREFIX=24
GATEWAY=192.168.102.1
DNS1=192.168.102.1

ZONE=public

2.桥接到网卡上,备份原网卡配置文件，修改原配置文件：

mv /etc/sysconfig/network-scripts/ifcfg-enp4s0 /etc/sysconfig/network-scripts/bak/ifcfg-enp4s0
vi /etc/sysconfig/network-scripts/ifcfg-enp4s0
TYPE=Ethernet
BOOTPROTO=none
NM_CONTROLLED=no
NAME=enp4s0
DEVICE=enp4s0
ONBOOT=yes
BRIDGE=br0

3.重启网络
systemctl restart network
(测试中，重启网络，联不上主机，主机电脑需要重启，就好了。不知道为啥，慎用！)

4.查看网络

 ifconfig 

br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.102.100  netmask 255.255.255.0  broadcast 192.168.102.255
        inet6 fe80::12e7:c6ff:fe40:8dc7  prefixlen 64  scopeid 0x20<link>
        ether 10:e7:c6:40:8d:c7  txqueuelen 1000  (Ethernet)
        RX packets 4308  bytes 329429 (321.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 3362  bytes 295573 (288.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp4s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::12e7:c6ff:fe40:8dc7  prefixlen 64  scopeid 0x20<link>
        ether 10:e7:c6:40:8d:c7  txqueuelen 1000  (Ethernet)
        RX packets 4310  bytes 389855 (380.7 KiB)
        RX errors 0  dropped 1  overruns 0  frame 0
        TX packets 3370  bytes 296229 (289.2 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
查看网桥：
 brctl show 
bridge name bridge id       STP enabled interfaces
br0     8000.10e7c6408dc7   no      enp4s0

通过网桥IP就可以访问主机。