Hi,
What are the results when you SSH to your affected host and run ethtool -i vmnic0 and repeat for all vmnic's. Below is a example of what you might see.
~ # ethtool -i vmnic0
driver: bnx2
version: 2.2.4d.v55.2
firmware-version: bc 5.2.3 NCSI 2.0.12
bus-info: 0000:03:00.0