VM's network connection state shows "Link Down" on the switchport portgroup

Products

• VMware vSphere ESXi

Issue/Introduction

•  VM's network state shows "Link Down" on the switch portgroup.
  
  
  
  
  
• net-stats -l shows MAC address as all zero's "00:00:00:00:00:00"
  
  

Environment

VMware vSphere 8.x

Cause

This is expected behavior if the virtual network adapter inside the guest operating system is disabled, causing ESXi to mark the vNIC link as DOWN and display the MAC address as all zeros.

Running ifconfig or ipconfig would ‘NOT’ list the network adapter, confirming that network adapter is disabled inside the guest OS.

Resolution

Ensure that the network adapter is enabled in the guest OS.

Windows:

via UI : Run cmd "ncpa.cpl" to open the "Network COnnection" window and enable/disbale network adpater.
via CLI : 

Run "netsh interface show interface" to list the network adapter".

To enable/disbale run the cmd <netsh interface set interface "Interface Name" enable>

Linux:

ifconfig ethX up

where X is the network adapter on VM ie eth0/eth1.