Intermittent Traffic Loss on vmk11 Interfaces in NSX Environments

Products

• VMware NSX

Issue/Introduction

• Users may experience intermittent network connectivity issues for virtual machines or services relying on specific VMkernel interfaces, such as vmk11.
  
  
• These symptoms typically manifest as packet drops that persist despite healthy physical uplinks and correct MTU configurations.
  
  
• Traffic may temporarily restore if a VM is migrated or power-cycled, particularly if Distributed Resource Scheduler (DRS) moves the workload to a different host.
  
  
• Continuous or intermittent packet loss observed on vmk11 while other interfaces (e.g., vmk10) remain healthy.
  
  
• vmkping tests show drops even with standard MTU sizes.
  
  
• Physical NIC statistics show zero Rx/Tx drops, and physical switch ports show no errors.

Environment

• VMware vSphere ESXi 7.x / 8.x
  
  
• VMware NSX

Resolution

To resolve this issue, please perform the following workaround.

1. Place the affected ESXi host into Maintenance Mode.
2. From the NSX Manager UI, navigate to System > Fabric > Nodes > Host Transport Nodes.
3. Select the affected host and click Remove NSX.
4. Wait for the removal process to complete and verify that vmk10 and vmk11 have been deleted from the host.
5. Select the host again and click Configure NSX (or Re-prepare) to reinstall the NSX components.
6. This process forces the creation of clean VMkernel interfaces.
7. Exit Maintenance Mode and verify connectivity using vmkping on the affected interface