vmxnet3 Adapters fail to get enabled on ESXi host

Products

• VMware vSphere ESXi

Issue/Introduction

• The vmxnet3 Adapters of VMs fail to get enabled on ESXi hosts
• On the ESXi host, the mac address of the impacted VM can be observed as 00:00:00:00:00:00 in the output of "net-stats -l" command.
• In the vmware.log file of the VM, below log will be observed:
  
  2025-03-17T09:30:16.392Z In(05) vcpu-0 - VMXNET3 user: failed to activate 'Ethernet0', status: 0xbad0001
  
  
• The host vmkernel.log will have below errors which indicate that the host is unable to MAP the Guest Tx/Rx rings for the VM via the XMAP call:
  
  2025-03-17T09:30:16.392Z In(182) vmkernel: cpu84:233407634)Vmxnet3: 11603: Failed to map the tx data ring for tq 3
• The host may also experience PSOD (KB 435767)

Environment

VMware vSphere ESXi

 

Cause

This is caused by XMap fragmentation/exhaustion for the VMXNet3 device.

Resolution

• Increase the default XMAP space to 64GB, followed by a host reboot:
  
  esxcli system settings kernel set -s "xmapGB" -v 64
  
  
• Increase P2M Buffer from 5 to 32 at host level.