The ESXi host web user interface is unavailable post a failed upgrade

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi host web user interface is unavailable. 
• ESXi host had a failed upgrade. 
• ESXi host cannot be pinged.
• Management network test is failing when performed via DCUI.
• IP address, Default Gateway, and VLAN configurations have been verified via console checks and match those of other cluster hosts.
• Running esxcli network nic list doesn't display the vmnics.
• Checking devices by running  vmkchdev -l | grep vmnic displays the network devices.
• Corresponding VIBS are present, validated using the following article: Determining Network/Storage firmware and driver version in ESXi 
   

Environment

ESXi 7.x
ESXi 8.x

Cause

In rare instances, during the ESXi upgrade or after replacing a new PCIe NIC adapter, the NICs are not recognized by the ESXi host.

Resolution

To fix this issue, perform a cold reboot of the ESXi host. If it does not resolve the issue, engage the hardware vendor.