We're proud to introduce a new Red Hat Access Labs app: KVM Bridge Configuration

By default, KVM uses Network Address Translation (NAT) networking through a libvirt-managed bridge called virbr0. You can use a bridged interface to get your guest box to appear as another host on the same network as the hypervisor.

This app is designed to help you configure a bridged network interface for KVM using Red Hat Enterprise Linux 5.4 or later. You will have two options:

1.Download an all-in-one script and execute it on the hypervisor:

#chmod +x kvm-config.sh
#./kvm-config.sh

2.Download a set of configuration files and perform a few steps to apply the changes:

Step 1: 
#ifdown eth0
Copy ifcfg-eth0 to the directory /etc/sysconfig/network-scripts/

Step 2: 
Copy ifcfg-br0 to the directory /etc/sysconfig/network-scripts/
#ifup eth0
#ifup br0

Step 3: 
Append the configuration snippet in sysctl.conf-part to file /etc/sysctl.conf
#sysctl -p /etc/sysctl.conf

Step 4:
#service libvirtd reload
#brctl show
#ethtool br0

Below is a screenshot of the app, but try it for yourself and have fun. And don't forget to let us know what you think! You can leave comments on the app info page.