VMXNET3 Network Adapter Missing in Windows VM

Products

• VMware vSphere ESXi

Issue/Introduction

A Windows VM with one or more VMXNET3 network adapters, one adapter may disappear in the guest OS, even though vCenter shows both adapters as connected. This can  happen randomly without known triggers or upon Guest OS reboot.

• One network adapter missing in Windows Device Manager.
  
  
  
• Both NICs are connected in vCenter.
  
• VM remains reachable over the network via the visible NIC.

 

Environment

VMware vSphere ESXi 8.0.x

Cause

This issue is related to the Windows guest OS and not the ESXi host or Broadcom NICs. Possible reasons include:

• Outdated or corrupt VMXNET3 driver.
• Windows policies or updates blocking the NIC.
• Guest OS misconfiguration for multiple NICs.

Resolution

Steps to verify and resolve the issue:

• Validate ESXi host and vSwitch configuration – no errors were observed.
• Check VM network adapter status in vCenter – both NICs connected.
• Examine guest OS device manager – verify which NICs are visible.
• Confirm driver version for VMXNET3 adapter.
• Update the VMXNET3 driver to the latest version by updating VMware Tools inside the Guest OS.
• Verify VM network settings in vCenter to ensure both NICs are connected.
• If network connectivity issues are observed beyond the missing NIC, consider performing a live packet capture

Contact the guest OS vendor (e.g. Microsoft) for further troubleshooting if the issue persists.