Chapter 11. Virtualized network devices

11.1. Configuring multiple guest network bridges to use multiple ethernet cards
11.2. Red Hat Enterprise Linux 5.0 Laptop network configuration

This chapter covers special topics for networking and network configuration with Red Hat Enterprise Linux Virtualization.

Most guest network configuration occurs during the guest initialization and installation process. To learn about configuring networking during the guest installation process, read the relevant sections of the installation process, Chapter 5, Guest creation overview.

Network configuration is also covered in the tool specific reference chapters for virsh(Chapter 19, Managing guests with virsh) and virt-manager(Chapter 20, Managing guests with Virtual Machine Manager(virt-manager)). Those chapters provide a detailed description of the networking configuration tasks using both tools.

Tip

Using para-virtualized network drivers improves performance on fully virtualized Linux guests. Chapter 12, Introduction to Para-virtualized Drivers explains how to utilize para-virtualized network drivers.

11.1. Configuring multiple guest network bridges to use multiple ethernet cards

Process to setup multiple Red Hat Virtualization bridges:

Configure another network interface using either the system-config-network application. Alternatively, create a new configuration file named ifcfg-ethX in the /etc/sysconfig/network-scripts/ directory where X is any number not already in use. Below is an example configuration file for a second network interface called eth1
```
$ cat /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
BOOTPROTO=static
ONBOOT=yes
USERCTL=no
IPV6INIT=no
PEERDNS=yes
TYPE=Ethernet
NETMASK=255.255.255.0
IPADDR=10.1.1.1
GATEWAY=10.1.1.254
ARP=yes
```
Copy the file, /etc/xen/scripts/network-bridge, to /etc/xen/scripts/network-bridge.xen.
Comment out any existing network scripts in /etc/xen/xend-config.sxp and add the line network-xen-multi-bridge.

Create a custom script to create multiple Red Hat Virtualization network bridges. A sample scripts is below, this example script will create two Red Hat Virtualization bridges (xenbr0 and xenbr1) one will be attached to eth1 and the other one to eth0. If you want to create additional bridges just follow the example in the script and copy/paste the lines accordingly:

#!/bin/sh
# network-xen-multi-bridge
# Exit if anything goes wrong.
set -e
# First arg is the operation.
OP=$1
shift
script=/etc/xen/scripts/network-bridge.xen
case ${OP} in
start)
	$script start vifnum=1 bridge=xenbr1 netdev=eth1
	$script start vifnum=0 bridge=xenbr0 netdev=eth0
	;;
stop)
	$script stop vifnum=1 bridge=xenbr1 netdev=eth1
	$script stop vifnum=0 bridge=xenbr0 netdev=eth0
	;;
status)
	$script status vifnum=1 bridge=xenbr1 netdev=eth1
	$script status vifnum=0 bridge=xenbr0 netdev=eth0
	;;
*)
	echo 'Unknown command: ' ${OP}
	echo 'Valid commands are: start, stop, status'
	exit 1
esac