[syslinux] Using DNS in pxelinux.cfg

[Jeffrey Hutzelman]

--On Tuesday, November 02, 2010 09:36:08 PM +0000 Matthew Macdonald-Wallace 
<lists at truthisfreedom.org.uk> wrote:

> Hi all,
>
> First time here, so please be gentle! :)
>
> I'm trying to configure a system that will pxeboot and retrieve a
> kickstart file from a server based on that host's macaddress as part of
> my Edison project[0] however I'm having issues getting the dns lookup to
> work and I'm hoping you can help!
>
> My pxelinux.cfg/default file is as follows:
>
> =======================
>
> default linux
> prompt 0
> timeout 1
> label linux
>         kernel /images/Centos-5.4-x86_64/vmlinuz
>         ipappend 2
>         append initrd=/images/Centos-5.4-x86_64/initrd.img
> ksdevice=bootif text serial=tty0 kssendmac
> ks=http://edison/api/kickstart/
>
> =======================
>
> However the image that pxeboots doesn't appear to support DNS lookups,
> regardless of the fact that my DHCP config pushes a DNS Server out to
> the PXE Client (proven using a liveCD running dhclient against the same
> server).  The only way I can get this to work is to change the "ks"
> stanza to the following:
>
> ks=http://ip.ad.dr.ess/api/kickstart/
>
> Is this a known issue, or am I missing something?

The 'ks=' argument is processed by anaconda, well after the kernel has 
booted and PXELINUX (and your PXE client) are out of the picture.  So, this 
really has nothing to do with PXE and everything to do with what happens 
afterwards.

I would suggest trying a fully-qualified hostname; the search domain 
configuration that allows that to work on a fully-installed machine (if it 
does) is not available in the installer.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+ at cmu.edu>
   Carnegie Mellon University - Pittsburgh, PA