Packet drops and timeouts intermittently seen on ESXi hosts using QLogic qedentv adapters

Products

• VMware vSphere ESXi

Issue/Introduction

• Virtual machines (VMs) experience intermittent network packet drops, application timeouts, and latency. This behavior is observed across multiple clusters and hardware vendors (e.g., Dell, Lenovo, Nutanix) using QLogic FastLinQ QL41xxx (qedentv) adapters.
  
• Intermittent application timeouts and packet drops observed at the Guest OS and ESXi host levels.
• vmkernel.log contains entries indicating driver firmware dumps:
  

  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1658(vmnic0-0)]Dbg bus dump Buffer size (in dwords) is 3177 Total Size 3181
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1680(vmnic0-0)]idle check result Buffer Size (in dwords) is 16266 Total Size 19451
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1680(vmnic0-0)]idle check result Buffer Size (in dwords) is 16266 Total Size 35721
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1702(vmnic0-0)]fifo dump Buffer Size (in dwords) is 150 Total Size 35875
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1723(vmnic0-0)]igu fifo dump Buffer Size (in dwords) is 342 Total Size 36221
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1744(vmnic0-0)]protection_override buffer size (in dwords) is 132 Total Size 36357
  2026-07-15T21:30:13.254Z cpu66:2097484)[qedentv_fw_collect_dump_size:1765(vmnic0-0)]fw_asserts buffer size (in dwords) is 187 Total size 36548
  2026-07-15T21:30:13.265Z cpu66:2097484)[qedentv_fw_collect_dump_size:1810(vmnic0-0)]MCP trace buffer size (in dwords) is 27864 Total size 64416

• Physical switch ports may not show a "link down" status despite connectivity loss.

Environment

VMware ESXi 7.x 
VMware ESXi 8.x

Cause

Physical network infrastructure issues, such as a faulty SFP module in the physical switch chassis. This instability triggers the qedentv driver to perform hardware resets and generate firmware dumps (GRC dumps) as it attempts to recover the link.

Resolution

• Identify and replace suspect SFP modules or cabling connected to the affected ESXi hosts.
• Ensure the qedentv driver and associated NIC firmware are aligned with the VMware by Broadcom Compatibility Guide
• To recover the host in this particular condition reboot the ESXi host.
• Provide the hex dumps generated during the resets to the hardware vendor for deep-dive analysis by the NIC manufacturer (Marvell/QLogic).

To stay updated on this situation, subscribe to the Broadcom knowledge article.