Can not PXE Boot in UEFI Mode

[jag880]

Hello there. We are trying to use a PXE server to automate Red Hat Enterprise Installations using Kickstart files. For whatever reason, we are unable to get this working with recent HP hardware (Laptops or Desktops). We have a RHEL 7.7 server setup running DHCP, TFTP, FTP services for our task. The booting clients appear to be unable to access/download the required boot file in UEFI mode. PXE boot works just fine in legacy mode on all the HP hardware we've tried. Our setup even works with all Dell hardware that we've tried. Only HP stuff. The following are the systems we have tried.

ZBook 14u G6

ZBook Studio G5

Z4 workstation.

Again, all of these work when booting in legacy/BIOS mode. For UEFI we have tried both with Secure boot on/off. But always get the following error.

>>Start PE over IPv4.

Station IP address is 192.168.2.6

Server IP address is 192.168.2.20

NBP filename is shim.efi

NBP filesize is 0 Bytes

PXE-E99:Unexpected network error.

So our clients are getting an IP address and see the boot file "shim.efi" but then appear to encounter a network error of some sorts when trying to transfer the file over TFTP. Do not understand this as it works perfectly in legacy and on non HP hardware. For the Zbook 14u G6 I did update the BIOS to the latest I could find (R70 Ver.01.02.01) Any help would be greatly.

[Stephanstoke]

Is your issue already resolved?

I have the same problem but with different setup: https://h30434.www3.hp.com/t5/Business-Notebooks/PXE-E99-Unexpected-network-error-on-HP-Elitebook-10...

[jag880]

No. I eventually gave up on it and went a different route for system deployments. I was only needing it to boot to the installation files that were stored on a network source. HP said it was RHEL's issue while RHEL said it was HP's issue. I went with RHEL's side on this as works like a charm on non HP equipment. 

[Stephanstoke]

Thanks for getting back to me.
For me it turn out to disable DMA in the bios under system settings.

Regards!