Im trying to setup a PXE boot server to deploy CloneZilla images easily, using pxelinux.0. I have a tftp-hpa server running on a server, I tested it with a client and it works fine. We are using a FortiNet router as the DHCP server, so I added that :

set option1 66 '3139322e3136382e302e313533'
set option2 67 '7078656c696e75782e30'

Which would translate to for the option 66, and pxelinux.0 for option 67. I dumped the DHCP offer packets to check, and that seems to be correct. When I try to boot an empty VMware workstation VM on PXE to check however, it does receive the options, but it asks the DHCP server ( for the file pxelinux.0, completely ignoring option 66. Is that somehow normal behavior ? I've seen mention of option 43 and 60, but I understood it's used only for Microsoft environments. Maybe I'm supposed to set those options to something anyway to make the option 66 used ?

1 Answer 1


Figured out a way to make it work. It looks like the option 66 isn't actually used by anyone, instead the next-server part of the protocol is used. Unfortunately, I can't change it on my version of the Fortinet firmware, it's automatically set to it's own address, so I added a policy to redirect traffic coming to port 69 (tftp) of the fortinet to the actual TFTP server, and it works perfectly. That's not a great solution, but at least it works.

  • Hello from 8 years in the future. I ran around in circles with this issue and actually disregarded this answer at first because I thought "surely this option 66 works as designed" but nope... server pxe process ignores it option 66 completely and the tftp server "MUST" live on the dhcp host or setup a relay like you have done. I'm curious if you've found a better solution since you first wrote this?
    – Rino Bino
    Mar 23, 2022 at 2:16

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