So, a 'PXE server' is nothing more then a DHCP server and some method of fetching files (historically, TFTP, but this is not a requirement). ISC DHCPD is prett

So, a 'PXE server' is nothing more then a DHCP server and some method of fetching files (historically, TFTP, but this is not a requirement). ISC DHCPD is pretty bulletproof. Many large carriers/ISPs use it, so scaling this end should be pretty straightforward. You'd probably want to statically configure leases for all your servers though. Pretty much all PXE roms built into NICs only support TFTP. I would use TFTP to load a iPXE, then use iPXE to load the operating system over something else (probably HTTP). Scaling HTTP is well understood (this is about the easiest HTTP scaling you can do, downloading a few static files). Nothing about this is hard to scale, nor does it require any special network setup.