PXE booting to a Windows WDS boot server from a Linux (or Infoblox) DHCP server

The University of Southampton is deploying a new Infoblox-based DHCP and DNS service. Underneath Infoblox is just a custom version of ISC DHCPD and ISC BIND. We also have a Windows-based WDS (Windows Deployment Services) network build server which we want to be used as the PXE build server. If you’re not using IP helpers, which most people don’t, this can be tricky.

The solution is to configure the “next-server” and “pxe-boot” server IP address in Infoblox. As far as I can tell this seems to set DHCP option 66 which is the TFTP boot server IP address. However you also need to set the boot filename – which seems to be DHCP option 67. If you’re using a Linux TFTP server and syslinux/pxelinux that filename should be set to ‘pxelinux.0’. The Windows TFTP server of course requires a different path.

It seems that for Windows WDS the path is ‘/boot/x86/wdsnbp.com’, except Windows uses backslashes, and just putting that path in does not work – you’ll end up with a TFTP access violation error. Instead you need to use backslashes, but escape the backslashes as ISC DHCPD will think you’re using an escape sequence. You also need to terminate the filename with a NUL character.

You’ll thus need something like this in your Infoblox GUI:

Screen Shot 2013-05-29 at 21.02.19

And then, voila, you should be able to use a PXE boot client onto a Windows Deployment Services PXE server from an Infoblox DHCP server.


  1. jsroberts@brilliantpc.com says:

    Boy we struggled with this for weeks now. Infoblox support and Microsoft couldn’t pinpoint the issue.

    changed our path from \boot\x86\wdsnbp.com to boot\\x86\\wdsnbp.com and WDS works great again.



  2. boethius says:

    Thanks for this as well. FYI I am not sure why that trailing \00 would ever be necessary but perhaps you can enlighten. boot\\x86\\wdsnbp.com by itself for the boot file seems to do the trick.


  3. Useful post, thankfully I had a working system using IP helpers direct to SCCM an I was able to pint point the fault within an hour of troubleshooting, then it was down to google and this post to fix it.

    Once again thank you


  4. Dan says:

    Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you Thank you! I have been trying to figure out for 2 days why the hell my clients cant PXE boot from my WDS server. We use infoblox as well for DHCP.


  5. Matt says:

    In infoblox, what are the DHCP options 66 and 67 suppose to be. Sorry, new to infoblox and PXE booting.


    1. David Bell says:

      Options 66 and 67 allow you to network boot (usually network install) systems. Option 66 is the hostname (well, IP address) of the TFTP boot server, and Option 67 is the filename on the server of the executable to boot.


  6. jfharry says:

    I have a DHCP Solaris with SCCM and it’s not work… 😦
    My macro DHCP have the options :
    TFTPsrvB : (Distribution Point SCCM)
    OpftBootF : SMSboot\\x64\\wdsnbp.com

    Can You help me ?


  7. Roberto says:


    if you could send a sample bootfile for a Linux tftp.
    The file is pxelinux.0


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