slackware-current/usb-and-pxe-installers/README_PXE.TXT

PXE: Installing Slackware over the network
==========================================


Introduction
------------

    When the time comes to install Slackware on your computer, you have a 
limited number of options regarding the location of your Slackware 
packages.  Either you install them from the (un)official Slackware CDROM or 
DVD, or you copy them to a pre-existing hard disk partition before starting 
the installation procedure, or you fetch the packages from a network server
(using either NFS, HTTP or FTP protocol).

    The number of available options for booting your Slackware installer is 
similarly limited: either you boot your computer from the bootable first 
CDROM of the Slackware CD set, or from the DVD, or using a USB stick.  There
is even loadlin, the DOS based Linux starter, but lets not concern ourselves
with the past today. Slackware 12.0 abandoned the floppy boot altogether.

    What if your PC is lacking a CDROM drive and refuses to boot from a USB
stick?  Brands of PCs are on the market today (ultra-portable laptops for
instance) that are unable to install Slackware the traditional way.  However,
these machines are commonly equipped with network peripherals, like bluetooth, 
wireless and wired network cards.  How to solve this dilemma? Buy an external
CD drive?

    Well, there is another way of booting your computer that the Slackware 
installer supports.  That is the 'network boot'.  Network boot, or PXE boot,
requires support from your computers network card and BIOS.  
Also, instead of installing packages from a Slackware CDROM set or DVD, you
will need a network server that can instruct your computer how to fetch those
packages from the network.

    In this README, I will show you how to perform an installation that uses
the network as the carrier medium, with a server on the local network that
holds the boot kernel and the root filesystem (which contains the setup
program), and also has all the Slackware packages.  This means, there is no
need for a floppy or CDROM drive.

    Be warned: setting it all up is not trivial, and you need more than a 
beginners level of Linux knowledge, but this text and the accompanying 
example scripts in the last section should get you up and running even if 
you do not completely understand what is going on :-)


PXE boot explained
------------------

    The commonly used method of booting a computer over the network is 
called PXE or 'Preboot Execution Environment'.  If you want your computer to 
boot using PXE, it needs a network card with PXE-capable firmware, and a 
BIOS that supports network boot.  Most modern network cards (and computers) 
sold on the market today support this.  When a computer boots from the 
network, it is the network card that downloads the bootloader, kernel and 
a filesystem - any Operating System that might already be installed on the 
computer will be untouched.  You can just as well boot a diskless computer 
using PXE - in fact this is how Thin Clients and the Linux Terminal Server 
Project work.

    Of course, the other end of the network needs our attention, too.  A 
PXE server needs to be available on the local network.  The PXE firmware in 
your computers network card will contact this server in order to fetch some 
kind of bootable program code and bootstrap itself.  What happens after the 
computer boots up has no longer anything to do with the PXE boot stage, it
is the bootstrapping process were interested in.
We will cover the requirements for such a server in one of the next 
paragraphs.


The stages of a Slackware PXE install
-------------------------------------

    The Slackware network installation process will be roughly as follows:

(1) You start the computer that is going to receive Slackware

(2) On startup, you make sure you select network boot in the BIOS startup -
    either by activating a custom startup sequence, or by entering a boot menu
    after pressing a function key like 'F12', or else by preselecting network
    boot as first option in the BIOS.

(3) When the computer boots, the network card activates its PXE code and 
    tries to contact a PXE server.  When such a server exists on the LAN,
    it will tell the card where to download a piece of bootable code, an
    Operating System kernel (the Slackware Linux kernel) and an initial
    ramdisk (aka initrd - the compressed root-filesystem image where the
    setup program, libraries and kernel modules are stored).
    You will see a page full of mumbo-jumbo as the card broadcasts on the
    LAN, and probes for possible candidate configurations to download;

(4) If a willing PXE server is found, your computer's network card will 
    then download a kernel and initrd, boot the Linux kernel, unpack the
    initrd into a ramdisk and start the Slackware installer's initialization
    sequence.  

    This is where you'll be in familiar territory again, since this is exactly 
    what happens if you had booted from a CDROM or a floppy.  But the fun is 
    not over...
    Since we booted the computer using code that did not originate from our 
    computer, we will have to fetch the remainder of the data - the Slackware 
    packages - from the network as well.  It's just that the freshly booted 
    Linux kernel has no idea how it came to be running on the computer: you 
    will have to initialize the network all over again.  The network card's
    PXE firmware has done its job and is no longer in the picture.  So:

(5) We need to load a kernel driver for our network card and locate a network 
    server that holds the Slackware package tree (called the "SOURCE").
    Currently, you can choose between installing from a NFS server, a Samba
    server or a HTTP/FTP server.  By starting setup and selecting one of
    these network package SOURCEs, you will get the opportunity to configure
    the network card.  If your network card is not supported by any of the
    available drivers, you are out of luck and will have to rethink your
    options.

(6) From here on, installation proceeds as usual, under the condition that 
    you select 'Install from NFS (Network File System)', 'Install from
    FTP/HTTP server' or 'Install from Samba share' as the source of the
    Slackware packages.


Workstation requirements
------------------------

As stated before, the requirements for the computer you want to install 
Slackware on, are as follows:

(1) Network card (non-wireless) with PXE firmware, supported by Slackware

(2) PC BIOS allowing to select 'network boot'

    No other requirements have to be met for a network install, other than 
those you'd already have to meet in order to be able to install and run 
Slackware.


Server requirements
-------------------

    This is the interesting part (well in my opinion at least - many people 
consider this as a dark art).  A PXE Server is really a mix of several 
components.  We need:

(1) A service that understands the BOOTP protocol.  BOOTP is a network 
    protocol somewhat like DHCP, and it is used by the PXE firmware to 
    broadcast on the network its desire to find a suitable server to download 
    the bootstrap code from.  The DHCP Server packages that are part of
    Slackware fulfill this requirement, since they talk BOOTP as well as DHCP.
    These packages are 'dhcpd' and 'dnsmasq'; pick the one you like most.

(2) A download service for the bootstrap code.  A TFTP (trivial file 
    transfer protocol) server is needed for this.  Slackware ships with
    an implementation of a TFTP server called 'tftpd-hpa' which does what
    we need.

(3) And for the Slackware installer, a NFS, HTTP, FTP or Samba server is
    required because we must perform a network install.  We can use
    Slackware's stock NFS, HTTP, FTP or Samba server for this.


Configuration of the BOOTP/DHCP/TFTP/NFS services
--------------------------------------------------

    We'll look at how to set up the DHCP, TFTP and NFS services on a 
Slackware computer so that they work together as a PXE server. It is left as
an excercise for the user to find out how to configure Apache (HTTP) or
proftpd (FTP) in case installation over HTTP or FTP is preferred.  In later
examples, I will assume that the following URL's are valid for your HTTP/FTP
server:
        http://192.168.0.1/mirror/slackware/slackware-13.37
        ftp://192.168.0.1/pub/mirror/slackware/slackware-13.37

    The server will run all required services, i.e. acts as the LANs 
DNS, DHCP, TFTP and NFS (or HTTP/FTP/Samba) server.  If you decide to
separate DHCP and TFTP services onto two different servers (it does not
matter where the NFS/HTTP/FTP/Samba server runs), I have included information
about what you should be aware of in the next section on DHCP.

    For ease of instruction, I will make a number of assumptions.  These 
assumptions are reflected in IP addresses and address ranges that I use in 
my examples, in the names of directories, computers and network domains.  
This means that if you use the examples in this article, you should make 
certain that you replace all occurrences of these specifics with values 
that apply to your own network.

(*) Our example network uses IP addresses in the range of 192.168.0.0 to 
    192.168.0.254.  This is equivalent to a network range 192.168.0.0/24 or 
    192.168.0.0/255.255.255.0.

(*) Our network server will have the IP address of 192.168.0.1 and the 
    default gateway is 192.168.0.10.  Server and gateway can be (but do not 
    need to be) the same physical machine.

(*) The IP address range that the DHCP server will use for leasing to 
    DHCP/BOOTP enabled computers is 192.168.0.50 to 192.168.0.100.
    This leaves enough room to have lots of machines with fixed IP addresses,
    if you need them.

(*) The DNS domain will be "my.lan".

(*) Directories are used as follows:
    Top level of the complete Slackware 13.37 directory tree (excluding
    the source code if you're short on disk space) is 
    "/mirror/slackware/slackware-13.37"

(*) The directory where we store the boot files for the TFTP server is 
    "/tftpboot/slackware-13.37"


DHCP
----

    You probably already have a DHCP server running on your network.  You 
can try and modify its configuration so that it will do want we want, or if 
that is impossible (for instance because the DHCP server is running on your 
DSL/Cable router) you could consider disabling that and setting up a 
Slackware DHCP server for your LAN with much enhanced functionality.

    Slackware includes the ISC DHCP server package (dhcpd).  Two example 
"/etc/dhcpd.conf" configuration files for this DHCP Server are included in the 
last section of the article.

    If you don't want to be bothered with fancy configurations but want a 
quick solution that will just work for your network, use the first (simple) 
example /etc/dhcpd.conf configuration file as well as the provided 
/etc/rc.d/rc.dhcpd start script and you'll be up and running in minutes.  
It requires no editing of files, the examples will work out of the box.

    If you know what you're doing and understand (more or less) how the 
DHCP server works, you can have a look at the second, more complex, 
/etc/dhcpd.conf example which has more features and offers control over 
what computers are allowed to do a network boot.

    The rest of this chapter deals with the setup of a complex DHCP 
configuration.

    By default, we should not allow network boots in our network (which is 
safer of course - imagine a computer that does an un-intended network boot 
and suddenly finds itself running the Slackware installer!).  In the 
/etc/dhcpd.conf configuration file, we add a 'group' section were we can add 
those computers that we allow as network boot clients; the typical host 
statement for a computer looks like this

host t43 {
    hardware ethernet 00:12:34:56:78:9a;
    fixed-address 192.168.0.3;
} 

    Nothing spectacular; a computer is defined by the network card's 
hardware address (MAC address) and we instruct the DHCP Server to always
assign it the same IP address.  The boot-specific parameters are all contained
in the 'group' block and look like this:

group {
  allow bootp;
  next-server 192.168.0.1;
  use-host-decl-names on;
  if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
    filename "/slackware-13.37/pxelinux.0";
  }

  host ABC {
    .....
  }

  host XYZ {
    .....
  }
}

    This enables the DHCP server to detect network boot clients that use PXE 
and serves them the PXElinux boot loader we make available at
"/slackware-13.37/pxelinux.0".  What this boot loader does will be explained
further down the article.

    The 'next-server' parameter contains the IP address of the TFTP server.  
This will often be identical to the DHCP server's IP address, but if you 
have a TFTP server that is running on a different IP address than the DHCP 
server (i.e. they run on separate servers) you will have to add the remote 
IP address instead, like this (assuming the TFTP server is running on IP 
address 192.168.0.254):

next-server 192.168.0.254;

    If you are running a version of the 'ISC' dhcpd program that is >= 3.0.3,
then the addition of a "next-server <ipaddress>;" line is mandatory.  For older
releases this was only needed if the TFTP and DHCP Servers actually had 
different addresses.

    If you fail to set the 'next-server' address, the 'siaddr' field in the 
data returned to the client is set to zero where in the past it would 
default to the DHCP server's own IP address (which often happened to be the 
IP address of the TFTP server as well).  The PXE client uses the 'siaddr' 
field to determine the IP address of the TFTP server and so the PXE booting 
will stall at the point of looking for a TFTP server.

    If you are already using 'dnsmasq' as your DNS/DHCP server, then the 
above instructions for the ISC DHCP server are not applicable to your 
setup. Instead, you have to configure dnsmasq with this equivalent parameter:

  dnsmasq --dhcp-boot=/slackware-13.37/pxelinux.0,"192.168.0.1",192.168.0.1

or add this line to your /etc/dnsmasq.conf:

  dhcp-boot=/slackware-13.37/pxelinux.0,"192.168.0.1",192.168.0.1

The IP address "192.168.0.1" occurs twice; they should always be identical,
and be the address of your TFTP server.


TFTP
----

    The tftpd service is managed by inetd.  Enable the line for tftpd in 
the file "/etc/inetd.conf" by removing the comment character at the beginning 
of the line:

  tftp  dgram  udp  wait  root  /usr/sbin/in.tftpd  in.tftpd -v -s /tftpboot -r blksize

and reload inetd:

  /etc/rc.d/rc.inetd restart

We need to create the directory /tftpboot which will hold the bootstrap 
files that tftpd will serve:

mkdir /tftpboot

    This directory is the root of a secure jail (the -s /tftpboot parameter 
in /etc/inetd.conf).  The tftpd service is now configured and running.  We 
just need to populate its root directory, but I"ll keep that for another 
paragraph.

As an alternative to in.tftpd, you may want to use the built-in tftp server
of dnsmasq. If you are already using dnsmasq as your DHCP server, this would
make sense.
Add the two following commandline parameters to your dnsmasq commandline:

  --enable-tftp --tftp-root=/tftpboot

or add the following two lines to your /etc/dnsmasq.conf file:

  enable-tftp
  tftp-root=/tftpboot

NFS
---

    You need to export the directory where you keep your local copy of the 
Slackware packages, for instance by adding this to /etc/exports:

/mirror/slackware      192.168.0.0/24(ro,sync,insecure,all_squash,subtree_check)

If your Slackware packages are located somewhere below /mirror/slackware
(like in our example network), the above line makes this directory tree
available (read-only) to NFS clients in the local network defined by the IP
address range 192.168.0.0/24.
If you had to add this line to your /etc/exports file, you will need to
restart the NFS server:

  /etc/rc.d/rc.nfsd restart

For simplicity's sake:
The remainder of this chapter is a bullet list of the steps required if you
just want to have this working and have no prior experience with NFS nor have
such a server running at the moment (remember that any pathnames/IP addresses
that are used here apply to our example network - adjust as needed):

(*) Create a file named /etc/exports with the following content:

      /mirror/slackware       192.168.0.0/24(ro,sync,insecure,all_squash)

(*) The directory mentioned in /etc/exports is the target where
    you copy (or move) your Slackware files to: The directory
    "/mirror/slackware/slackware-13.37" should be the root of the Slackware
    tree, containing such files as ChangeLog.txt and subdirectories like
    "slackware" (or "slackware64" if you are working with the 64bit port)
    and "kernels".

(*) Make the NFS server startup script executable so that the NFS server 
    will start on every boot:

      chmod +x /etc/rc.d/rc.nfsd

    Start the NFS server (so you don't have to reboot already):

      /etc/rc.d/rc.nfsd start


PXELinux configuration
----------------------

    The previous paragraph described in generic terms how to setup the TFTP
service, but it did not tell you how to populate the TFTP directory structure.
Network clients that request boot files from the TFTP server will receive
the files that are present in this directory structure.

    PXELinux is much like isolinux, which is the bootloader that is used 
for the bootable Slackware CDROM #1.  In fact, both programs are written by 
the same author and are available in Slackware via the syslinux package.  

The tftp directory structure:

    As you can see in the DHCP section, the DHCP server has been configured
to offer any interested PXE client (i.e. your computers network card) the
file "/slackware-13.37/pxelinux.0" - this file contains the bootable code
that first downloads and starts a Linux kernel, and then downloads and
extracts the root filesystem containing the setup program and everything
else that we need.  This filename "/slackware-13.37/pxelinux.0" indicates
a pathname relative to the root of the TFTP server.  The PXE client will
use the tftp protocol to fetch this bootloader.  So this is what we do:
create this directory "slackware-13.37" and copy the required files into it.
First, the pxelinux bootloader itself:

  mkdir /tftpboot/slackware-13.37
  mkdir /tftpboot/slackware-13.37/pxelinux.cfg
  cp /usr/share/syslinux/pxelinux.0 /tftpboot/slackware-13.37/

Also, we need the files from the Slackware CDROM that show the 
informative messages in the beginning.  Assuming your local copy of the 
Slackware release can be found in "/mirror/slackware/slackware-13.37"
(change paths in the below commands if your location is different) :

  cp /mirror/slackware/slackware-13.37/isolinux/message.txt /tftpboot/slackware-13.37/
  cp /mirror/slackware/slackware-13.37/isolinux/f2.txt /tftpboot/slackware-13.37/

Very important: we need the initial ramdisk image (initrd.img) and the pxelinux configuration file that contains the instructions for the PXE clients:

  cp /mirror/slackware/slackware-13.37/isolinux/initrd.img /tftpboot/slackware-13.37/
  cp /mirror/slackware/slackware-13.37/usb-and-pxe-installers/pxelinux.cfg_default /tftpboot/slackware-13.37/pxelinux.cfg/default

And lastly, we need all the kernels that the Slackware installer lets you
choose from:

  cp -a /mirror/slackware/slackware-13.37/kernels /tftpboot/slackware-13.37/


Trying it out
-------------

    You now have a fully configured PXE server.  Try it out!  Take a 
computer that is able to do a network boot, start it, and watch it go 
through the motions of contacting the PXE server, downloading the PXE boot 
code and presenting you with the familiar Slackware installation screen! 
From there on you're on familiar grounds: choose a kernel, and off you go.

    If you're not familiar with network installations, here are some hints:

    The installer uses UDEV to load the required driver(s) for your network
card.  You can login as root, use (c)fdisk to create your partitions and
start 'setup'.  By the time you get to the point where you select your
preferred method of network installation, the installer will ask you to
supply network configuration parameters (IP address, netmask, gateway).
If a DHCP server was found on your local network, you will have the
alternative option to use DHCP and automatically configure the interface.

    ====================================================================
    If for whatever reason you do not want to use UDEV, you can pass
    the parameter 'noudev' at the boot commandline.  This will cause the
    installer to fallback to the old behaviour where you have to load the
    kernel driver for your network card yourself.  You do have to run
    the command 'network' which is the interactive program that allows
    you to pick a driver or let Slackware probe the card and load the
    correct driver.  You can press 'L' to get a listing of all available
    network drivers that you can select from (not all of them will be used
    in the automatic probe).  If the network program fails to detect the
    card, and you know what driver your card needs but don't see it listed,
    you're out of luck!  If you forget to run the 'network' program before
    you start 'setup', the network configuration dialog will run it when
    the time comes, so that you do not have to start all over.
    ====================================================================

    Once you get to the SOURCE dialog, you can select either 'Install from NFS
(Network File System)', 'Install from FTP/HTTP server' or 'Install from
a Samba share' depending on which of those you have confgured for use
and have available.  You will need to supply a couple of values for IP
Addresses and the network server directory.

As a first exercise, here are values to use with a NFS server (for our
example network):

Your IP Address (pick any unused): 192.168.0.111
Your netmask:                      255.255.255.0
The gateway:                       192.168.0.10
NFS server address:                192.168.0.1
Slackware directory on NFS server: /mirror/slackware/slackware-13.37/slackware

Next, some values to use with a FTP server (for our example network):

Your IP Address (pick any unused): 192.168.0.111
Your netmask:                      255.255.255.0
The gateway:                       192.168.0.10
FTP server address:                ftp://192.168.0.1
Slackware directory on ftpserver:  /pub/mirror/slackware/slackware-13.37

Next, example values to use with a HTTP server (for our example network):

Your IP Address (pick any unused): 192.168.0.111
Your netmask:                      255.255.255.0
The gateway:                       192.168.0.10
HTTP server address:               http://192.168.0.1
Slackware directory on webserver:  /mirror/slackware/slackware-13.37

Finally, example values to use with a Samba share (for our example network):

Your IP Address (pick any unused): 192.168.0.111
Your netmask:                      255.255.255.0
The gateway:                       192.168.0.10
Samba share:                       //192.168.0.1/mirror
Slackware directory on webserver:  /slackware/slackware-13.37

    Note #1 - if you chose automatic network configuration using DHCP in an
earlier step, you can probably use actual hostnames instead of IP addresses.
This will depend on your LAN setup; if DHCP and DNS services are correctly
configured, every network host will have a hostname that resolves to it's
IP address.

    Note #2 - in the case of the NFS server, you will have to supply the
path to the Slackware package tree _including_ the '/slackware' subdirectory.
For HTTP and FTP servers, it is sufficient to supply the root of the
slackware-13.37 tree and leave the 'slackware' subdirectory out. The installer
will figure out where the packages are.

    From this point onwards, the installation proceeds just as when the 
SOURCE would have been a CDROM.

Good luck!
Eric Hameleers.


Example configuration scripts
-----------------------------


First example "/etc/dhcpd.conf"
-------------------------------

A simple /etc/dhcpd.conf for your DHCP Server where all computers are allowed
to boot from the network using PXE.

# dhcpd.conf
#
# Configuration file for ISC dhcpd
#
# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
authoritative;
ddns-update-style none;

# Allow bootp requests
allow bootp;

# Point to the TFTP server:
next-server 192.168.0.1;

# Default lease is 1 week (604800 sec.)
default-lease-time 604800;
# Max lease is 4 weeks (2419200 sec.)
max-lease-time 2419200;

subnet 192.168.0.0 netmask 255.255.255.0 {
    option domain-name "my.lan";
    option broadcast-address 192.168.0.255;
    option subnet-mask 255.255.255.0;
    option domain-name-servers 192.168.0.1;
    option routers 192.168.0.10;
    range dynamic-bootp 192.168.0.50 192.168.0.100;
    use-host-decl-names on;
    if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
      filename "/slackware-13.37/pxelinux.0";
    }
}


Second example "/etc/dhcpd.conf:
--------------------------------

A more advanced /etc/dhcpd.conf file for your DHCP server where you can 
specify exactly which computers are allowed to boot from the network using 
PXE (but you will have to collect their MAC addresses yourself and put them 
into separate host{} entries):

# dhcpd.conf
#
# Configuration file for ISC dhcpd
#

# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
authoritative;
ddns-update-style none;

# Ignore bootp requests:
ignore bootp;

# option definitions common to all configured networks...
option domain-name-servers 192.168.0.1;

subnet 192.168.0.0 netmask 255.255.255.0 {
    option domain-name "my.lan";
    option broadcast-address 192.168.0.255;
    option subnet-mask 255.255.255.0;
    option routers 192.168.0.10;
    # We reserve the range 192.168.0.1 to 192.168.0.49 for static IP addresses
    pool {
      # Known clients (i.e. configured with a 'host' statement)
      # that request an IP address via DHCP
      range 192.168.0.50 192.168.0.100;
      # Default lease is 1 week (604800 sec.)
      default-lease-time 604800;
      # Max lease is 4 weeks (2419200 sec.)
      max-lease-time 2419200;
      deny unknown clients;
    }
    pool {
      # Guests
      range 192.168.0.150 192.168.0.200;
      # Default lease is 8 hours (28800 sec.)
      default-lease-time 28800;
      # Max lease is 24 hours (86400 sec.)
      max-lease-time 86400;
      deny known clients;
    }
}

# Hosts which require special configuration options can be listed in
# host statements. If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.

# Fixed IP addresses can also be specified for hosts. These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP. Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.

# === Group definitions =============================================
# Define groups of computers that you want to give special attention.

group {
  # Non-PXE machines

  # Default lease is 1 week (604800 sec.)
  default-lease-time 604800;
  # Max lease is 2 weeks (1209600 sec.)
  max-lease-time 1209600;

  #host penguin {
  #  hardware ethernet xx:xx:xx:xx:xx:xx;
  #  fixed-address 192.168.0.2;
  #}
}

group {
  # PXEboot
 
  # Default lease is 1 day (86400 sec.)
  default-lease-time 86400;
  # Max lease is 2 days (172800 sec.)
  max-lease-time 172800;

  # Allow bootp requests for this group:
  allow bootp;

  # Point to the TFTP server (required parameter!):
  next-server 192.168.0.1;

  # If you want to log the boot process, you will need to configure
  # your logserver to allow logging from remote hosts.
  #option log-servers 192.168.0.1;

  use-host-decl-names on;

  if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
    filename "/slackware-13.37/pxelinux.0";
  }
  else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
    filename "/slackware-13.37/kernels/hugesmp.s/bzImage";
  }

  host t43 {
    # Add your computer's MAC Address here:
    hardware ethernet yy:yy:yy:yy:yy:yy;
    fixed-address 192.168.0.3;
  }
}  # end of PXEboot group


RC script for DHCP
------------------

A Slackware start/stop script for the DHCP server that you can save as 
"/etc/rc.d/rc.dhcpd".

Don't forget to make the script executable:

  chmod +x /etc/rc.d/rc.dhcpd

You can add the following lines to /etc/rc.d/rc.local so that the DHCP 
service starts when your server boots:

if [ -x /etc/rc.d/rc.dhcpd ]; then
  # Start the DHCP server:
  /etc/rc.d/rc.dhcpd start
fi

This is the content of the file "/etc/rc.d/rc.dhcpd":

#!/bin/sh
#
# /etc/rc.d/rc.dhcpd
#      This shell script takes care of starting and stopping
#      the ISC DHCPD service
#

# Put the command line options here that you want to pass to dhcpd:
DHCPD_OPTIONS="-q eth0"

[ -x /usr/sbin/dhcpd ] || exit 0

[ -f /etc/dhcpd.conf ] || exit 0

start() {
      # Start daemons.
      echo -n "Starting dhcpd:  /usr/sbin/dhcpd $DHCPD_OPTIONS "
      /usr/sbin/dhcpd $DHCPD_OPTIONS
      echo
}
stop() {
      # Stop daemons.
      echo -n "Shutting down dhcpd: "
      killall -TERM dhcpd
      echo
}
status() {
  PIDS=$(pidof dhcpd)
  if [ "$PIDS" == "" ]; then
    echo "dhcpd is not running!"
  else
    echo "dhcpd is running at pid(s) ${PIDS}."
  fi
}
restart() {
      stop
      start
}

# See how we were called.
case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  restart)
        stop
        start
        ;;
  status)
        status
        ;;
  *)
        echo "Usage: $0 {start|stop|status|restart}"
        ;;
esac

exit 0


========================================================
Author:
  Eric Hameleers <alien@slackware.com> 21-mar-2011
Wiki URLs:
  http://www.slackware.com/~alien/dokuwiki/doku.php?id=slackware:pxe