[syslinux] pxelinux failing to boot kernel

[Greg Mitchell]

Hoping to find some help debugging an issue I'm having.

I have 3 machines that are PXE booting Ubuntu. This morning they were
running 17.04 and I decided to upgrade them to 17.10. All 3 machines use
the same motherboard with onboard intel nic. After the upgrade, I made the
necessary changes to the pxelinux.cfg file to add the new kernel. Now only
2 of the 3 machines boot. The other machine will not boot using the new
kernel, only the old one. When I select the new kernel, it tftps the kernel
and initrd (I see two "Loading..." lines printed to the screen, also
verified in the tftpd logs). Then it just hangs, and doesn't print a single
kernel message. All the motherboards have the latest BIOS and have the
Intel Boot Agent that they shipped with (doesn't appear to be upgradable).
I really have no idea what else to try. Any ideas on how to debug this?