Installation guide

Bridged networking with libvirt

Creating the bridge

Create or edit the following two network configuration files. These steps can be repeated (with different

names) for additional network bridges.

1. Change to the network scripts directory

Change to the /etc/sysconfig/network-scripts directory:

# cd /etc/sysconfig/network-scripts

2. Modify a network interface to make a bridge

Edit the network script for the network device you are adding to the bridge. In this example,

/etc/sysconfig/network-scripts/ifcfg-eth0 is used. This file defines eth0, the

physical network interface which is set as part of a bridge:

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

Tip

You can configure the device's Maximum Transfer Unit (MTU) by appending an MTU variable

to the end of the configuration file.

MTU=9000

3. Create the bridge script

Create a new network script in the /etc/sysconfig/network-scripts directory called

ifcfg-br0 or similar. The br0 is the name of the bridge, this can be anything as long as the

name of the file is the same as the DEVICE parameter, and that it matches the bridge name used

in step 2.

DEVICE=br0

TYPE=Bridge

BOOTPROTO=dhcp

ONBOOT=yes

DELAY=0

Warning

The line, TYPE=Bridge, is case-sensitive. It must have uppercase 'B' and lower case 'ridge'.

4. Restart the network

After configuring, restart networking or reboot.

# service network restart