I work in the refurb division of an ewaste recycling company[0]. To prepare a machine for sale, the drive needs to be wiped, and (optionally) an OS loaded. Wiping happens in WipeOS[1], which loads when you PXE boot on the internal company network. To install an OS, I have a separate network on my desk that will load iVentoy[2] when PXE booted, where I can further boot from ISOs I have on my server, but I almost always install Linux Mint. With those 2 things, I can largely do my job without fumbling with and losing USB drives.

I have 2 16 port switches on my desk, with over a dozen ethernet cables plugged into each. The yellow cables will PXE boot WipeOS, and the black ones PXE boot iVentoy.

[0] https://www.ebay.com/str/evolutionecycling

[1] https://www.wipeos.com/

[2] https://www.iventoy.com/en/index.html

God help you if you actually want to install an operating system.

PXE is such a vital capability for working with on-prem servers. But it's ten different things which all have to play nicely together. Every time I build a PXE system I feel like I'm reinventing the universe in my tiny subnet.

You can extend this with secure boot (using your own keys) to sign the entire UKI file, so your firmware will authenticate the full "disk" image that it boots into.

I think at one point we were even using distcc to use the clients to speed up rebuilds while iterating on the game. I should revisit that with iPXE and icecream.

Thankfully modern BIOSes tend to implement HTTP boot option, where you can point to any HTTP or HTTPS URL (as long as the URL ends with ".efi", which is a pretty dumb limitation if you ask me).

PXE is a big improvement over the boot EPROMs that we needed to install on our NICs back in the day. Those would get an address via DHCP and then TFTP the boot image, and boot it.

I've had some trouble with PXE boot that's been caused by STP. If your PXE boot server has, or is behind a bridge with STP turned on, it can prevent the client from booting. I think this has something to do with the STP "learning state", but turning off STP on the bridge can solve the problem, as long as you're sure that you will not be creating any network loops on the affected interfaces.

There's also a new "https boot", which is supposed to be a PXE replacement, but TLS certs have time validity windows, and some clients may not have an RTC, or might have a dead CMOS battery, and those might not boot if the date is wrong.

Had great experience using PXE to boot HPC farms, mounting the OS from a NAS and using only a local disk in the machine for tmp and other writable locations. I am not sure how 'diskless' linux works these days on rocky flavours but was solid in centos 5 through 7.