[ILUG] pxeboot & dhcp

[Darragh Bailey]

I asked before on the irc channel whether there was anyway to do
pxebooting where I had my linksys box currently providing the dhcp
without completely changing my network, and no one was able to 
provide an answer. Those that responded thought that I would have to
change to having my PC do the dhcp.

I've since found that you can set additional DNSMasq options on the 
dd-wrt that allowed me to specify my PC to act as a pxeboot server 
without having to have dhcp run on my and disable it on the router when
trying to netboot a laptop (doing some rescue work on a laptop missing a
critical file and having a broken CD/DVD drive).

Some others may find the following option useful, enable DNSMasq for
DHCP and add the following line to the Additiona DNS Options under
Administration -> Services:
dhcp-boot=pxelinux.0,<machaine name>,192.168.1.10

I left the section for machine name blank in my case, it's not actually
necessary. Detailed man page link:
http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html


In any case, I was doing some reading on syslinux and from reading it I
seems that since bootp is an extension and a separate request that it
might be possible to have 2 dhcp instances running within the same
network. 1 which takes care of assigning addresses, i.e. the instance
running on my linkSys wireless device and should basically ignore any
bootp requests, and a second instance that I can start on my PC along
with tftpd only when I need to, and is configured to only handle bootp
requests.

I haven't looked at it closely enough, so I don't know if dhcp even 
allows you to do this as part of the protocol standard and additionally 
whether it is then actually implemented to allow this for the dhcpd that 
would be installed on my PC.

Anyone tried anything like this before?

-- 
Darragh

"Nothing is foolproof to a sufficiently talented fool."