bootp

Also was popular for some Sun diskless workstations -- although the protocol was bootp instead of pxe.

Then install the OS from the regular console port over the network with bootp/tftp/http.

This is a pretty common pattern with netbooting; some will bootp rather than rarp, sometimes you use tftp to fetch something that can do an http fetch, etc.

...turns out you don't need local storage at all: if you already run a NAS you can bootp the RasPi over the network!

It took some work to find the right propeller heads at Softlayer, but eventually we understood each other and the bootp listeners got turned off for our subnets.

I also remember that the remote install required bootp, tftp, and password-less root rsh!