Syslinux - Jan 2010 - pxelinux and WDS

Hello,

We are trying to set up a configuration with pxelinux on a linux machine and
WDS, allowing us to be free to boot linux netboot installers from the tftp
server. We have validated that pointing our dhcp server to the wds server works
perfectly.
Our idea was to use pxechain.com to launch the wdsnbp.com kernel as below :
label windows
        KERNEL pxechain.com
        APPEND <ip address>::\Boot\x86\wdsnbp.com

wdsnbp.com loads perfectly from the WDS server but our problem is that WDS uses
dhcp to find which is the next server to load the next part of the WDS boot
process (pxeboot.com) and as the dhcp next-server points to our linux server it
does not work, there's a loop. I thought that it was the work of pxechain
(i.e. rewrite the next server in memory to prevent making those kinds of loops).

We have seen that this set up as been reported successful by some people over
the internet. Have we missed an option in the dhcpd config or elsewhere to allow
this configuration to work ?

Sincerely,

Julien Garet

--On Thursday, January 21, 2010 09:01:45 PM +0100 Julien Garet 
<julien.garet at inria.fr> wrote:
> Hello,
>
> We are trying to set up a configuration with pxelinux on a linux machine
> and WDS, allowing us to be free to boot linux netboot installers from the
> tftp server. We have validated that pointing our dhcp server to the wds
> server works perfectly.  Our idea was to use pxechain.com to launch the
> wdsnbp.com kernel as below : label windows
>         KERNEL pxechain.com
>         APPEND <ip address>::\Boot\x86\wdsnbp.com
>
> wdsnbp.com loads perfectly from the WDS server but our problem is that
> WDS uses dhcp to find which is the next server to load the next part of
> the WDS boot process (pxeboot.com) and as the dhcp next-server points to
> our linux server it does not work, there's a loop. I thought that it
was
> the work of pxechain (i.e. rewrite the next server in memory to prevent
> making those kinds of loops).
Yes, that's exactly PXECHAIN's job.  As you note, it rewrites the
response
in memory, but of course it can't affect the response the DHCP server will 
send if some later part of the boot process does a new DHCP request (for 
example, most OS installers will do this eventually).

We've been using it to start WDS for some time, using configuration nearly 
identical to yours.  You shouldn't need any special configuration on the 
DHCP server, but I'm not sure if there's anything unusual that has to be
done on the Windows side to make this work.

-- Jeff

Julien Garet a ?crit :
> Hello,
>
> We are trying to set up a configuration with pxelinux on a linux machine
and WDS, allowing us to be free to boot linux netboot installers from the tftp
server. We have validated that pointing our dhcp server to the wds server works
perfectly.
> Our idea was to use pxechain.com to launch the wdsnbp.com kernel as below :
> label windows
>         KERNEL pxechain.com
>         APPEND <ip address>::\Boot\x86\wdsnbp.com
>
> wdsnbp.com loads perfectly from the WDS server but our problem is that WDS
uses dhcp to find which is the next server to load the next part of the WDS boot
process (pxeboot.com) and as the dhcp next-server points to our linux server it
does not work, there's a loop. I thought that it was the work of pxechain
(i.e. rewrite the next server in memory to prevent making those kinds of loops).
>
> We have seen that this set up as been reported successful by some people
over the internet. Have we missed an option in the dhcpd config or elsewhere to
allow this configuration to work ?
>   
Hey florent,

That's very surprising as I did exactly the same for installing Windows 
2008 servers and it worked very nice.
Are you sure that pxechain.com is coming from the same version as your 
pxelinux.0 ?
If yes, what release are you using ?

Another question about your DHCP. Does the dhcp server runs on a linux 
host or on the windows one ? If its running under linux, what 
product/release are you using ?
Could you show us its configuration ?

Erwan,