vCenter provides three additional counters at the host level. It can track packet receive errors, packet transmit errors, and unknown protocol frames. The counters are provided at either the host or vmnic level. They are not provided at the switch or port group levels.

This means you cannot gauge the performance at the port group or switch levels easily using vCenter:

ESXi network counters

Just like vCenter, vRealize Operations also does not provide counters at the standard switch or port group level. This means you cannot aggregate or analyze the data from these network objects' points of view. This is one reason why you should use Distributed Switch. It simply has a much richer monitoring capability.

Usage, Data Received Rate, and Data Transmit Rate are all available at the host level and at the individual NIC level. For readability, only vmnic3 and the host are shown in this screenshot:

ESXi network metrics in vCenter

You should expect the values for packets dropped and unknown packet frames to be 0. A packet is considered unknown if ESXi is unable to decode it and hence does not know what type of packet it is. Discuss with your network admin if you are seeing either a dropped packet or an unknown packet.

The packets dropped and unknown packet frames counters are available at the host level and individual NIC level. For readability, only vmnic1 and the host are shown in this screenshot:

ESXi network metrics in vCenter

The key counters to track for ESXi are consistent with the key counters for a VM. Again, vCenter does not provide the total packets dropped and the equivalent of the Workload counter. I've kept the table cell blank for ease of comparison. Here's the table: