In https://tianocore-docs.github.io/edk2-UefiDriverWritersGuide/draft/5_uefi_services/52_services_that_uefi_drivers_rarely_use/5210_installconfigurationtable.html

The sample code is WRONG.

Status = gBS->InstallConfigurationTable (
                &gEfiNetworkInterfaceIdentifierProtocolGuid_31,
                &UndiConfigTable
                );

The & in &UndiConfigTable is wrong. The result is that the installed pointer points at the stack (the location of the UndiConfigTable pointer), not the allocation (the memory that UndiConfigTable references). There is no compiler error or warning for this problem.

When people use this code as their sample, they're likely to make a mistake that wastes a lot of time to debug.