OK, after eight hours of screwing around I give -- I have to start asking around and this place seems likely to have some folk who know what they're talking about.
Environment: Simple simple setup of a stand alone ESXi v5.5 server, all hardware is approved, including a dual Intel 82574L and three guest VMs. No big deal.
Problem: One of the physical adapters on the dual port Intel 82574L, vmnic0, will not come up. It shows up in the vSphere client. I can add or delete the adapter from any vSwitch. I get no error messages as I manipulate or configure this physical adapter. But no matter what I do, the adapter will not come up. The darn thing just sits there taking up space.
The other physical adapter, vmnic1, is up and running just fine on the default vSwitch0. The VMkernel Port is attached to vSwitch0 and the Network Management port is "attached" to vmnic1 at the Direct Console screen. I don't see how VMkernel might play into the problem but figured I'd mention it anyway.
Any thoughts would be appreciated.
The attached is a screen shot of the vSphere client.