Excessive packet drops reported on ESXi 8.0.3 with Broadcom 25GB NICs

Products

• VMware vSphere ESXi

Issue/Introduction

Broadcom 25GB network adapters (bnxtnet) on ESXi 8.0.3 hosts may report high numbers of dropped packets in vCenter performance charts and Aria Operations. While some reports are due to a telemetry regression, actual performance impact can occur due to driver and firmware misalignment.

Symptoms:

• Aria Operations and vCenter show significant received packet drops (RX) on ESXi hosts.
• The esxcli network nic stats get -n vmnicX command shows inflated or unrealistic Rx counters.
• High vCPU utilization is observed during peak network loads.
• Virtual machines experience intermittent network latency or throughput degradation.

Environment

VMware vSphere ESXi 8.0.3

Cause

• A regression in the bnxtnet driver (v236.1.128.0) causes hardware queue stats to update incorrectly after quiesce or activation operations, leading to erroneous telemetry.
• Additionally, running this driver with older firmware (e.g., 22.x or 23.x) leads to buffer management inefficiencies and physical layer packet drops.

Resolution

This issue is fixed in bnxtnet driver version 238.x and higher. For Dell environments, the certified stack including Firmware 36.11.73.00 and Driver 236.1.228.0 also resolves the performance impact.

1. Identify current driver and firmware versions using esxcli network nic get -n vmnicX.
2. Verify the supported firmware version for your driver on the VMware Compatibility Guide.
3. Upgrade the bnxtnet driver and firmware to the certified versions.

Additional Information

• For Unrealistically high Rx counters telemetry issue, see Unrealistically high Rx counters on the pNICs of ESXi hosts.