Hi Kevin,
Thank you for your patience.
Regarding your question , Mellanox only guarantees a valid connection when using Mellanox products from end to end .
Therefore using other products than Mellanox products in the environment cannot be guaranteed be functional .
Please note that we have never tested tested this setup.
The tested and supported devices are listed in release notes of the firmware of the card.
For your convenience we please refer to the URL below (Section 1.2.3 Validated and Supported 4GbE Cables)
http://www.mellanox.com/pdf/firmware/ConnectX3Pro-FW-2_36_5000-release_notes.pdf
Thanks and regards,
~Martijn