7.3. Installing guests with PXE
- Create a new bridge - Create a new network script file in the/etc/sysconfig/network-scripts/directory. This example creates a file namedifcfg-installationwhich makes a bridge namedinstallation.Copy to Clipboard Copied! Toggle word wrap Toggle overflow Warning The line,TYPE=Bridge, is case-sensitive. It must have uppercase 'B' and lower case 'ridge'.Important Prior to the release of Red Hat Enterprise Linux 5.9, a segmentation fault can occur when the bridge name contains only uppercase characters. Please upgrade to 5.9 or newer if uppercase names are required.
- Start the new bridge by restarting the network service. Theifup installationcommand can start the individual bridge but it is safer to test the entire network restarts properly.service network restart # service network restartCopy to Clipboard Copied! Toggle word wrap Toggle overflow 
- There are no interfaces added to the new bridge yet. Use thebrctl showcommand to view details about network bridges on the system.brctl show # brctl show bridge name bridge id STP enabled interfaces installation 8000.000000000000 no virbr0 8000.000000000000 yesCopy to Clipboard Copied! Toggle word wrap Toggle overflow Thevirbr0bridge is the default bridge used bylibvirtfor Network Address Translation (NAT) on the default Ethernet device.
 
- Add an interface to the new bridge Edit the configuration file for the interface. Add the- BRIDGEparameter to the configuration file with the name of the bridge created in the previous steps.- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow After editing the configuration file, restart networking or reboot.- service network restart - # service network restart- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Verify the interface is attached with the- brctl showcommand:- brctl show - # brctl show bridge name bridge id STP enabled interfaces installation 8000.001320f76e8e no eth1 virbr0 8000.000000000000 yes- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Security configuration Configure- iptablesto allow all traffic to be forwarded across the bridge.- iptables -I FORWARD -m physdev --physdev-is-bridged -j ACCEPT service iptables save service iptables restart - # iptables -I FORWARD -m physdev --physdev-is-bridged -j ACCEPT # service iptables save # service iptables restart- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Note Alternatively, prevent bridged traffic from being processed by- iptablesrules. In- /etc/sysctl.confappend the following lines:- net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 - net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Reload the kernel parameters configured with- sysctl.- sysctl -p /etc/sysctl.conf - # sysctl -p /etc/sysctl.conf- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Restart libvirt before the installation Restart the- libvirtdaemon.- service libvirtd restart - # service libvirtd restart- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
				For virt-install append the --network=bridge:installation installation parameter where installation is the name of your bridge. For PXE installations use the --pxe parameter.
			
Example 7.3. PXE installation with virt-install
The steps below are the steps that vary from the standard virt-manager installation procedures. For the standard installations rsee Chapter 8, Guest operating system installation procedures.
- Select PXE Select PXE as the installation method.
- Select the bridge Select Shared physical device and select the bridge created in the previous procedure.
- Start the installation The installation is ready to start.
 
     
    