Confirming FEC CL74 settings for Broadcom BCM57414 adapters in ESXi 8.0

Products

• VMware vSphere ESXi

Issue/Introduction

You need to verify if the Broadcom BCM57414 10/25Gb adapter is correctly respecting and utilizing the Forward Error Correction (FEC) CL74 (Fire Code) setting within an ESXi 8.0 environment.   

FEC is used to improve link stability and signal integrity for 25Gb links. By default, the NIC settings are set to auto-negotiate, meaning the adapter retrieves the FEC configuration directly from the connected network switch port.

Environment

Host: VMware ESXi 8.0   

Hardware: Broadcom BCM57414 10/25Gb adapters   

Supported FEC Modes: * CL74 (Fire Code / Base-R FEC): Often used for shorter distances or copper (DAC) cables.   

CL91 / CL108 (Reed-Solomon FEC): The IEEE 802.3by standard for 25G.

Cause

Successful FEC utilization depends on configuration consistency across the hardware stack. For the NIC to respect the CL74 setting, the following dependencies must be met:   

The network switch port must support and be actively configured for CL74.   

Driver and firmware versions must be current and compatible.   

Configuration must be identical on both ends of the link to prevent connectivity failure.

Resolution

To ensure the NIC is respecting the CL74 setting, follow these verification steps:

Verify Switch Configuration: Confirm the physical switch port is explicitly set to CL74 (Fire Code).

Confirm Controller Support: The Broadcom BCM57414 controller architecture natively supports both CL74 and Reed-Solomon (CL91/CL108) modes.   

Check for Auto-Negotiation: Ensure the adapter is set to auto-negotiate so it can receive the CL74 instruction from the switch.   

Use Diagnostic Utilities: You can use manufacturer-specific utilities (such as niccli) to confirm the active FEC logic. Note that many Broadcom utilities use Clause 91 logic for 25G RS-FEC, so ensure you are specifically identifying CL74/Base-R for Fire Code verification.

Additional Information

Broadcom Ethernet Network Adapter User Guide

Broadcom NetXtreme-E User Manual

Switch Vendor Naming: Be aware that different switch vendors may use unique terminology; for instance, Juniper may refer to CL108 as fec108.