20.44. kb-00043: Secure Boot Shim Bootloaders Fail With Proxy DHCP in UEFI Mode Booting

20.44.1. Knowledge Base Article: kb-00043

20.44.2. Description

Booting a machine in UEFI mode with Proxy DHCP will cause the machine to enter the GRUB command line. The boot process stops at this point.

GRUB does not request additional configuration files.

20.44.3. Solution

Due to a bug in the upstream Grub2 code, grub2 does NOT handle Proxy DHCP messages in UEFI mode. This is not directly fixable. To make this work for non-secure boot environments, one can override the bootloader to use the unsigned, but functional, ipxe.efi bootloader. The bootloaders parameter can be used to change globally or by profile for a set of machines. Additionally, one could use the bootenv-customize parameter to alter a specific bootenv globally or by profile for a set of machines.

For Secure Boot Mode, there is currently not a valid solution.

20.44.4. Additional Information

Additional resources and information related to this Knowledge Base article.

20.44.4.1. See Also

RedHat Bug tracking this issue: https://bugzilla.redhat.com/show_bug.cgi?id=1809246

20.44.4.2. Versions

v4.4.0 and beyond content packs have this problem.

20.44.4.3. Keywords

Proxy, DHCP, UEFI, Grub2

20.44.4.4. Revision Information

KB Article     :  kb-00043
initial release:  Tue Jul  7 15:24:50 CDT 2020
updated release:  Tue Jul  7 15:24:50 CDT 2020