Unable to connect migrated VMs/newly deployed VMs to network with "Failed to connect virtual device Ethernet ‘X’ "

Products

• VMware NSX-T Data Center

Issue/Introduction

User unable to connect newly-deployed VMs or migrated VMs to the network and received error as "Failed to connect virtual device Ethernet ‘X’ "

vmware.logs

2024-10-24T12:26:31.467Z In(05) vcpu-0 - VMXNET3 user: failed to activate 'Ethernet3', status: 0xbad0006
2024-10-24T12:26:31.467Z In(05) vcpu-0 - VMXNET3 user: Activate request failed for device 3.
2024-10-24T12:26:31.467Z In(05) vcpu-0 - VMXNET3 user: failed to activate 'Ethernet4', status: 0xbad0006
2024-10-24T12:26:31.467Z In(05) vcpu-0 - VMXNET3 user: Activate request failed for device 4.

vmkernel.logs

2024-10-24T12:26:31.467Z cpu34:35421438)Vmxnet3: 17019: Failed to attach port 0x60001f0 to ENS with status Limit exceeded

Environment

VMware NSX-T Data Center 3.x

VMware NSX 4.x

Cause

• ENS polling mode has the limitation of 128 ports per ENS switch irrespective of the number of lcores configured.
• Validate the ENS connected ports count on the ESXI host with the command  nsxdp-cli ens port list | wc
• If the value exceeds limit 128 then new VMs on the ESXi host will not be able to connect to network 

Resolution

• There is no workaround.
• User can switch to Interrupt mode as it does not have port limitation, but the latency is less guaranteed than polling mode.
• Downtime of Application/VM is required for switching ENS mode
  
  

Additional Information

If the errors aren't matching, Please validate KB article Link for further troubleshooting.