Dennis HilkLinux diagnosticsDE

Ethernet & networking

Mellanox ConnectX-3 / MT27500 family

ConnectX-3 is a core adapter family with a separate Ethernet driver layer. A visible Mellanox PCI function alone does not show whether its configured port is operating as Ethernet or another supported fabric.

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On this page
  1. Overview & identity
  2. Driver & binding
  3. Firmware
  4. Read-only diagnostics
  5. Limitations & related issues
  6. References

Overview & identity

The core table explicitly labels the matching constant as MT27500/ConnectX-3; the header resolves it to 1003. ConnectX-3 Pro and virtual functions have different IDs.

Curated identifiers
pci 15b3:1003

A numeric match establishes a candidate family within the reviewed evidence. Marketing names, board variants, subsystem conditions and successful operation remain separate questions.

Driver & binding

mlx4_core owns the PCI function. The separate mlx4_en module supplies Ethernet networking when built and applicable; its absence is not the same observation as a missing PCI core driver.

  • mlx4_core — kernel driver/module candidate
  • mlx4_en — kernel driver/module candidate

Detected, bound, operational: learn the difference

Firmware

Device/revision dependent

The adapter’s resident firmware and configured port personality matter. No universal host-loaded firmware path is established by this core-table review; do not substitute an unrelated Wi-Fi firmware package.

Inspect firmware packaging on your distribution

Read-only diagnostics

Run one displayed command at a time. Replace uppercase placeholders with the affected device, interface or module from your own output. Commands are never executed here. Read-only output can still contain private identifiers.

Check the PCI function and bound driver

lspci -nnk -s BDF

Replace BDF with the domain:bus:device.function address. Look for [15b3:1003] and Kernel driver in use. mlx4_core in Kernel modules is only a candidate, not proof of binding.

Identify the network interface driver

ethtool -i INTERFACE

Replace INTERFACE with the real interface name. Driver and bus-info connect this interface to its device. A displayed firmware-version is adapter information; it does not prove a file was loaded. Candidate: mlx4_core.

Compare supported modes with the current link

ethtool INTERFACE

Supported/advertised link modes describe capability or negotiation offers. Speed, Duplex and Link detected describe the current link, not measured throughput. An unsupported query is a limitation of the interface/driver.

Separate PCIe transport from Ethernet speed

sudo lspci -vv -s BDF

Elevated access may be needed. Root can expose the full PCI configuration. If PCIe capabilities exist, compare LnkCap with LnkSta: maximum and negotiated PCIe speed/width are different from Ethernet speed. Legacy PCI or virtual functions may omit these fields.

Limitations & related issues

Port mode, adapter firmware and cable/transceiver identity can determine whether an Ethernet interface appears. Neither this PCI pair nor a loaded RDMA module proves Ethernet carrier.

These guides are linked for relevant observations, not as known defects of every device in this family.

Choose a hardware diagnostic workflow · Inspect a log excerpt in Fix Lab

References

Source review records a checked implementation or document, not a reproduced hardware test. Version-specific tables do not establish a minimum kernel or guaranteed operation.