Connectx-2 or connectx-3 not linking to network. No IP. No link light.

None of my Connectx-2 or Connectx-3 single port fiber cards will connect to my network.

Windows server, all versions, and Windows 10 client, all shows the cards operational but not connected and assigns a generic IP. Same with Linux Mint.

Plug in modules are operational as they will connect switches together.

All jumpers are good as they connect my switches together.

When plugged into the network, no link light but lasers are on.

Firmware is up to date.

I’ve tried 4 different motherboards with the same result.

Dual port wired Ethernet cards operate in the slot.

They did work once upon a time.

I’m at whits end.



Hi Charlie,

Is your driver also up to date?

Please make sure to install the proper version.

For linux - install MLNX_OFED from:

For Windows - install WinOF from:

Based on the information provided, I understand that the NICs are plugged into a switch, is that correct?

In this case, please check that the NICs ports & switch type is configured to Ethernet.

You can use the following article:

In addition, please check the cable used, make sure it is a validated and supported cable based on the latest Release Notes of the firmware in use.

Best Regards,


Firmware is up to date.

Just installed the MLNX_OFED from the provided link.

Windows does show ETH mode.

Still no joy.

What is strange is there isn’t even a link light.

Connecting switch to switch there is a link light, but not when connecting Connectx-3 to the module in the switch.

Fibers are correct and operational.

I have a generic fiber to CAT 5 Ethernet converter and the Connectx-3 will not connect using it either.

Hi Charlie,

Please note that ConnectX-2 adapter is EOL (end-of-life) and EOS (end-of-support).

Regarding ConnecX-3, please provide the following information:

  • Part number of the card
  • Part number of the switch
  • Part number of the cable

Please go over MLNX_OFED & WinOF release notes to find the supported operating systems.

WinOF release notes:

MLNX_OFED release notes: