@AeonLucid Awesome debugging information!!! Lots of thumbs up for you. I am a bit late now but I did see the post just now. Funny that but I had the exact same thing happening with my home router when trying to debug some other iPXE stuff at home. It seams like there are DSL routers out there which send ‘next-server’ in their DHCP OFFER/ACK without handing a filename to the client. I am not sure why they do (and I guess most don’t). So your client asks for PXE boot. Gets next-server from the router DHCP and your proxy. It seams to be fine in the first run where Intel PXE ROM boots up but as iPXE comes up it uses the next-server send by your router instead of the proxy one. Run wireshark on your FOG server and you should see it in the DHCP packets broadcasted by your router (original firmware).

Instead of flashing the router you could have also build your own iPXE binary with a customized script - I talked to Tom and we might add that at some point anyway, now that we know more people see this.

Let me know if you want to know more about custom iPXE…