[syslinux] Using DNS in pxelinux.cfg

[Gene Cumm]

On Tue, Nov 2, 2010 at 17:36, 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?
>
> Kind regards,
>
> Matt
>
> [0] http://github.com/proffalken/edison/

Try resolv.c32 to test how you're doing things.  I know that at least
some DNS servers I've used don't add your domain for you (domain or
search in /etc/resolv.conf).  I just used PXELINUX 4.03 with
resolv.c32 from the official package and it could resolve
"www.google.com" with no issue.  I then also tried to test another
name that should have had the local domain added to it and it just
seemed to hang, repeatedly sending the query (without local domain)
with no response.

Try qualifying the name you're using.  I'm not sure if PXELINUX was
ignoring my domain or never attempts appending the domain without some
more research.

-- 
-Gene