Is there a list of OpCodes anywhere for the ConnectX 4 Lx?

I’m trying to bring a link between a Cisco switch and a ConnectX 4 LX using a Mellanox MFM1T02A-LR transceiver on the Mellanox side with a Cisco SFP-10G-LR on the switch side. Windows thinks the link is up (and the card is reporting strong light) but I’m not getting bi-directional communication. Both sides are sending, but neither is seeing the other. MLXLink is reporting Status Op Code of 15, Group Op Code of PHY FW, and Bad Signal Integrity. Is there a list of the Op Codes that I can reference? My fiber is passing good light. It acts like a driver issue, but I tried with 2.50, 1.80, and 1.90 and got the same results.

Hello Brad,

Thank you for posting your question on the NVIDIA/Mellanox Community.

Based on the information provided, please try the following → Force the speed on the switch to 10G and check if the link comes up.

If you still are experiencing link issues, we need to further debug this issue through a valid Mellanox Support ticket (Valid support contract needed), which can be opened by sending a mail to

Thank you,

~NVIDIA/Mellanox Technical Support

Thanks for the idea. I set the Cisco side to 10G and unfortunately, I get the same results. I also tried forcing the Mellanox to 10G, but sadly, there was no change.