This is an example of setting up persistent network installs of Ubuntu 20.04 (Not deploying installs over the network.)
Date Published: 2020/05/21
pfSense (DHCP Server)(192.168.1.1)
Ubuntu 20.04 (Data Host Server)(192.168.1.2)
Ubuntu 20.04 (XPE Client)(192.168.1.50)(pxe1)
DHCP IP Reservation already assigned for both Host and Client machines.
I had to reboot the Host Server for everything to work.
For a live system log:
I had an issue with LXD failing during boot on the PXE Client, as I wasn't using it, I removed it.
To setup additional installs, repeat these steps and replace pxe1 with a shortname for each other install in both tftproot and nfsroot. Be sure to update the IP Address as well.
You can also do the client setup once and copy it to a new folder: