@jaapvdpol Well lets see if we can get a few things sorted out here.

Scale: I have not seen an install yet with 100 storage nodes. Each storage node will need to be managed at some point in time.

I kind of see this as a two phase project.

The initial push to move from windows to linux. Will you have boots on the ground at each location to do this? If yes they can bring a mobile deployment server with them (laptop kitted with what they need for imaging). If you are trying to do this all remote I can see it taking a while to complete. Post upgrade to linux. From time to time you may need to image failed computers. How will you handle that? Have a fog server at each site? Will you train local folks to be able to do this? Or is a drop ship a new system and they return the failed one for repair a bit of a better solution? Now I’ve used a raspberry pi for a fog server to image low volume systems. But that is before the prices of those critters when crazy. You think about it, with a site of 20 computers, you might, and I say ‘might’ reimage 1 computer a year. Is there value in having 100 storage nodes? I’m not saying one way or the other is right, just think about what you are trying to achieve and how much management work you are willing to do.

Now in regards to dnsmasq, that is a service we can install on the FOG server. With our configuration it will send out pxe boot information to the local subnet its connected to. You don’t need to touch anything on the router or network. So when the mobile fog server arrives, so does the pxe boot information. When the mobile fog server leaves, so does the concept of pxe booting. In this design (mobile deployment server) the target computers are not designed to pxe boot through the fog server, but instead a tech sitting in front of the computer presses F10 or F12 during booting to get to the efi boot manager where the tech picks pxe boot.

Understand I’m just trying to tell you what’s possible. Since I don’t know 100% of your use case I can only give suggestions based on how FOG works.