To configure a bridge on CentOS 7 or RHEL 7, you need to create a file with bridge configuration (for example, ifcfg-brX) and modify the file for the physical interface (for example, ifcfg-ethX). The following steps describe how to set up a bridge on both CentOS 7 and RHEL 7. We show examples for configuring bridge devices that either obtain IP addresses using DHCP or statically.
Install the bridge-utils package.
yum install bridge-utils
Go to the /etc/sysconfig/network-scripts directory:
cd /etc/sysconfig/network-scripts
Open the network script for the device you are adding to the bridge and add your bridge device to it. The edited file should look similar to the following:
DEVICE=eth0
# change the hardware address to match the hardware address your NIC uses
HWADDR=00:16:76:D6:C9:45
ONBOOT=yes
BRIDGE=br0
NM_CONTROLLED=no
Note
The device name may vary. See the .Create a new network script in the /etc/sysconfig/network-scripts directory called ifcfg-br0 or something similar. The br0 is the name of the bridge, but this can be anything as long as the name of the file is the same as the DEVICE parameter, and the name is specified correctly in the previously created physical interface configuration (ifcfg-ethX).
Note
Choose names and use them consistently for all NCs (both the file name and the in the file).DEVICE=br0
TYPE=Bridge
BOOTPROTO=dhcp
ONBOOT=yes
DELAY=0
If you are using a static IP address, the configuration will look similar to:
DEVICE=br0
TYPE=Bridge
BOOTPROTO=static
IPADDR=static_IP_address
NETMASK=netmask
GATEWAY=gateway
ONBOOT=yes
Enter the following command:
systemctl restart network.service