Installing PXE

Much of the credit for this piece goes to m'mannn Nick 'Franga' Fratangelo, alias the PXE Pixie, who did most of the research and experimentation.

Prerequisites

• A working ISC DHCP - the DHCP service must be installed and working
• The PXE/TFTP Service goes on the DHCP Server (requires the dhcpd Daemon)
• The Ports Collection must be installed
• A working internet connection for grabbing updates

Software Required

• DHCP Service (ISC-DHCP3-Server) - as above
• TFTP-HPA from the ports collection
• PXE Linux Package syslinux-3.11.tar.gz (1.44MB, or updated equivalent)
• Not all installs are downloaded to the /src directory

1. Install the Ports Collection

2. Install the TFTP Service

 This port has installed the following files which may act as network
      servers and may therefore pose a remote security risk to the system.
/usr/local/bin/tftp
/usr/local/libexec/in.tftpd

3. Create the TFTP Directories

4. Edit inetd.conf

#tftp dgram udp wait root /usr/libexec/tftpd tftpd -l -s /tftpboot

tftp dgram udp wait root /usr/libexec/tftpd tftpd -l -s /tftpboot -u nobody /

5. Setting up the TFTP Directories for PXE

6. Configuring PXE

PROMPT 1                              (gives a user prompt)
DEFAULT local                         (default label to boot)
DISPLAY defaultmessage                (message to display to the user)
TIMEOUT 100                           (timeout before booting to default)

label local                           (first label for localboot)
    LOCALBOOT 0                       (boots local disk)

label netboot                         (second label)
    KERNEL memdisk keeppxe            (which kernel to load, i.e. memdisk)
    APPEND initrd=images/netboot.img  (which image to load into memdisk)

label ghost                           (third label)
    KERNEL memdisk keeppxe            (which kernel to load, i.e. memdisk)
    APPEND initrd=images/ghost.img    (which image to load into memdisk)

Don't include the stuff in brackets in the default file.

So..default is the default menu file which the PXE system will boot, if the user doesn't type anything at the boot: prompt. Note the 100 timeout = 10 seconds. As soon as the user types one character on the workstation, the boot: prompt will wait indefinitely for that [enter] key..

After the first four lines, the rest of the file defines the labels and what to do if one is selected. Each labels points to a corresponding .img file, which is actually an image of a floppy disk (more below). If the user types local [enter] at the boot: prompt, the label tells the system to boot to the local hard disk. But if the user types netboot, then the label points it to the netboot.img and the contents of that file are executed. Add as many labels/.img files as required to perform various functions.

MEMDISK is a kernel loading program which manages the extraction and execution of the *.img file.

Next edit the default messages file..

vi /tftpboot/pxelinux/messages/default

..and add some friendly text:

Welcome to our PXE system
This is a message to you..

7. Modifying the DHCP service to use TFTP/PXE

# dhcpd.conf

# Allow PXE BootP
allow booting;
allow bootp;

# option definitions common to all supported networks...
option domain-name "it.net";
option domain-name-servers 10.0.0.1, 202.7.15.10;
ddns-update-style none;

default-lease-time 600;
max-lease-time 7200;

# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;

# Settings
option subnet-mask 255.0.0.0;
option broadcast-address 10.0.255.255;
option routers 10.0.0.2;
option domain-name-servers 10.0.0.1, 203.50.2.71;
option domain-name "it.net";
next-server 10.0.6.204;
filename "/pxelinux/pxelinux.0";

# Subnet Information
subnet 10.0.0.0 netmask 255.0.0.0 {
        range 10.0.6.1 10.0.6.230;
     range dynamic-bootp 10.0.7.1 10.0.7.230;

        }

next-server 10.0.6.204;
- this is the tftp/pxe/dhcp server's IP Address

filename "/pxelinux/pxelinux.0";
- this is the pxe system's filename (actually inside /tftpboot/pxelinux/pxelinux.0)

range 10.0.6.1 10.0.6.230;
- the standard dynamic ip lease range

range dynamic-bootp 10.0.7.1 10.0.7.230;
- the standard bootp/pxe dynamic ip lease range

8. Creating a floppy disk image

PXE Tweaks

References