Description of problem:
We are getting repeated complaints from customers that after reading the OSP-Director installation guide, they are getting the impression that the Provisioning network may be a tagged VLAN instead of a native VLAN. This is only possible on a subset of hardware that has BIOS support for PXE boot over VLAN, and not all vendors that support such a feature support it well enough to work with OSP-Director. We should change the documentation to make this clear.

Version-Release number of selected component (if applicable):
OSP 8 beta

Actual results:
The current wording says: "The Provisioning network provides DHCP and PXE boot functions to help discover bare metal systems for use in the Overcloud. This network should ​ideally use a native VLAN on a trunked interface so that the director serves PXE boot and DHCP requests."

Expected results:
We need to make it clear that only a certain subset of hardware will support PXE booting from a VLAN. I would change the above to something like:

"The Provisioning network provides DHCP and PXE boot functions to help discover bare metal systems for use in the Overcloud. Typically, this network must use a native VLAN on a trunked interface so that the director serves PXE boot and DHCP requests. Some server hardware BIOS's support PXE boot from a VLAN, but the BIOS must also support translating that VLAN to a native VLAN after booting, otherwise the Undercloud will not be reachable. Only a small subset of server hardware supports this feature fully."

Additional info:
We don't have a list of hardware that supports the necessary 802.1q translation in the BIOS. We do know that some BIOS controllers, such as that included in the latest Dell DRAC controllers, only support VLANs for the initial PXE boot, and the image will fail to reach the network after the image is booted. This has caused confusion and lost time for customers and deployers who expected this feature to work.