Joerg,

you are right. I have installed ESXi6.7 from Dell ISO. And now Driver and firmware combination is not matching.

In fact the firmware number do not even match with the firmware reported by Dell. This is worst thing.

It gives me a strong feeling driver is owned by VMware. This also explains why Driver is not there on Dell site irrespective it is async or not.

NOTE: For recommendations on latest combination of supported driver and firmware refer to OEM vendor matrix.

VMware Knowledge Base

But the driver is not here on Dell site. This sound funny. VMware Support suggests we are not responsible for Driver and Dell says we only offer firmware. This is chicken and egg problem but at the cost of customer money.