After a day and a half of troubleshooting why my NIC was showing down in VMware ESXi 6 even though it had green lights on both ends of the fiber and my Cisco 8500 switch said the circuit was up-up, I finally found the answer.
Gee, the Cisco SFP-10G-LRM SFP+ module I use throughout my network isn't compatible in the Intel NIC. Apparently I need an Intel E10GSFPLR SFP+ module in the NIC.
Of course this should work with the SFP-10G-LRM on one end and the E10GSFPLR on the other end, but can anyone verify this?