option domain-name "d";
option domain-name-servers 192.168.0.10,192.168.0.1;
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.0.255;
option routers 192.168.0.1;
host testbox {
hardware ethernet 00:0c:29:20:63:ad;
fixed-address 192.168.0.88;
}
After restarting my DHCP/BOOTP server I booted the VM and saw the following in my logs;
dhcpd: DHCPDISCOVER from 00:0c:29:20:63:ad via eth0 dhcpd: DHCPOFFER on 192.168.0.88 to 00:0c:29:20:63:ad via eth0Therefore DHCP is working, and offering the machine the specified IP. Now we just need to configure the bootstrap, or BOOTP, element. After some investigating in the man pages I found the following section:
BOOTP Support
Each BOOTP client must be explicitly declared in the dhcpd.conf file. A very basic client declaration will specify the client
network interface's hardware address and the IP address to assign to that client. If the client needs to be able to load a boot
file from the server, that file's name must be specified. A simple bootp client declaration might look like this:
host haagen {
hardware ethernet 08:00:2b:4c:59:23;
fixed-address 239.252.197.9;
filename "/tftpboot/haagen.boot";
}
OK, we need to provide the boot file via the "filename" argument. This raises two questions;
TFTPD_ROOT="/var/tftp"Put simply all files are served from this location. Ok, solved question 1, now question 2. This proved to be a bit more involved. After reading over a Wikipedia article on PXE [5] I found that I was in need of a "Network Bootstrap Program" or NBP. A quick browse of the external links led to my next investigation - PXELINUX [6].
host testbox {
hardware ethernet 00:0c:29:20:63:ad;
fixed-address 192.168.0.88;
filename "/pxelinux.0";
next-server 192.168.0.10;
}
The third is also pretty trivial in accordance with that shown below;
From "{ How do I Configure PXELINUX? }"
First, it will search for the config file using the hardware type (using its ARP type code) and address, all in lower case hexadecimal with dash separators; for example, for an Ethernet (ARP type 1) with address 88:99:AA:BB:CC:DD it would search for the filename 01-88-99-aa-bb-cc-dd. Next, it will search for the config file using its own IP address in upper case hexadecimal, e.g. 192.0.2.91 -> C000025B (you can use the included progam gethostip to compute the hexadecimal IP address for any host.) If that file is not found, it will remove one hex digit and try again. Ultimately, it will try looking for a file named default (in lower case). As an example, if the boot file name is /mybootdir/pxelinux.0, the Ethernet MAC address is 88:99:AA:BB:CC:DD and the IP address 192.0.2.91, it will try: /mybootdir/pxelinux.cfg/01-88-99-aa-bb-cc-dd /mybootdir/pxelinux.cfg/C000025B /mybootdir/pxelinux.cfg/C000025 /mybootdir/pxelinux.cfg/C00002 /mybootdir/pxelinux.cfg/C0000 /mybootdir/pxelinux.cfg/C000 /mybootdir/pxelinux.cfg/C00 /mybootdir/pxelinux.cfg/C0 /mybootdir/pxelinux.cfg/C /mybootdir/pxelinux.cfg/default ... in that order.Therefore for my specific installation I created the following file:
/var/tftp/pxelinux.cfg/01-00-0c-29-20-63-adFor step four I populated this file after quickly looking over the "{ How do I Configure SYSLINUX? }" section [7]. Because this is to be used for further development I only really wanted a "dummy" configuration. Therefore I used the following:
SAY Welcome...... DEFAULT helloworld label helloworld kernel hello.c32The kernel "hello.c32" comes with PXELINUX under the "samples" directory. It can be used in accordance with the following:
The "kernel" doesn't have to be a Linux kernel; it can be a boot sector or a COMBOOT fileTherefore step five required placing "hello.c32" in my TFTP root directory ("/var/tftp") resulting in the following files and directory structure:
/var/tftp /var/tftp/pxelinux.cfg/01-00-0c-29-20-63-ad /var/tftp/pxelinux.0 /var/tftp/hello.c32
Last updated: 28th March 2007
