@chief Its been a few days now so lets make sure we are on the same page.
You have the dhcp server (MS Windows??), the FOG server, and the PXE booting client all on the same vlan for testing.
The target computer PXE boots, then the iPXE kernel is sent to the target computer. But now iPXE complains about “No configuration methods succeeded”
If this is the case, my initial reaction is that this might be a spanning tree issue (assuming this happens on the dell computer).
Why?, because the target computer pxe boots and the undionly.kpxe (or ipxe.efi) is sent to the target. computer. To do that the PXE rom must be able to talk to the dhcp server to get an IP address and boot file name. When the iPXE kernel launches it momentarily resets the network interface causing the link light to drop (wink) for a second. If spanning tree is enabled on that switch port and it is not configured for one of the fast STP protocols, the port won’t go into the forwarding state for 27 seconds. By then the iPXE kernel has given up stating “No configuration methods succeeded” or in english - “I can’t get a dhcp address on any network interface”.
A quick check for a spanning tree issue is to place a dumb (unmanaged) switch between the target computer and the building network switch. If it boots into the FOG menu with the unmanaged switch in line then you need to speak to your networking group to confirm that one of the fast STP protocols are enabled. This is not a FOG issue but a networking issue.