Network cards are not found in vCenter/ESXi UI as vmnics when passthrough is enabled

Products

• VMware vSphere ESXi

Issue/Introduction

• One or more NICs are not being displayed in the vCenter/ESXi UI when going to physical adapters list via Host->Physical adapters->Configure
  
• Checking the cli option to list vmnics is also not listing the affected NIC ports as vmnics:  SSH to ESXi host -> run "esxcli network nic list"
• The PCI device/NIC in question is Enabled for passthrough: Select ESXi host -> Configure -> Hardware -> Passthrough-Enabled devices and find the NIC/PCI Device in question
  

Cause

This is expected behavior when PCI Device/NIC has passthrough option enabled.

Resolution

If you want to change passthrough option, follow these steps:

1. Check the status of the PCI device in the host: Click on the host, Go to “Configure” -> “Hardware” -> “PCI Devices”
2. Ensure to have the "Passthrough" status as "Disabled". In our case it was enabled. If the Passthrough status of PCI device is in enabled state, Click on “Toggle Passthrough” and it changes to disabled state.