I'm testing the 40GbE connection with a normal FDR cable with Cisco Nexus 5672.
You have to enable this on the cisco:
n5672a# show int e2/5 transceiver details
transceiver is present
type is QSFP Unknown Type-(unknown)
name is Mellanox
part number is MC2207312-005
revision is A2
serial number is
nominal bitrate is 14100 MBit/sec
Link length supported for copper is 5 m
cisco id is --
cisco extended id number is 0
Hi Chris, I was just trawling through the questions on this site and found your question about interoperability between Cisco and Mellanox switches. This problem is now solved by the introduction of Mellanox LinkX Cisco compatible cables. These cables are the official LinkX types made compatible with Cisco, Juniper, Arista and others and will be launched on June 8th 2015 in EMEA (following shortly after in Asia and USA). The cables will be available through usual Mellanox channel partners.
ProLabs (UK) Ltd and Mellanox have partnered to bring this new product line to the market.
If you want further info please do not hesitate to contact me directly.
Prolabs (UK) Ltd