3 Replies Latest reply on Jul 2, 2014 11:23 AM by m.gharaei

    How to configure Mellanox card to accept breakout cable connection (4x10Gbps)?



      We installed 2 Mellanox NIC on serverA and 2 of them on serverB.


      Mellanox NIC info:


      Model: MCX354A

      PSID: MT_1090110019

      Driver: mlx4_en

      version: 2.2-1.0.1 (Jun 13 2014)

      firmware-version: 2.31.5050




      -Dell poweredge R720xd

      -CPU: 32 CPU each 2.9 GHz (Sandy Bridge): Numa0: 0-2-4-...30,


      -6 slot PCIe 8GT/s (16 lane)

      -RAM: 128 GB DDR3

      -OS: ubuntu 12.04 LTS (Kernel:

      -four Intel SFP+ cards with ixgbe driver

      We are going to test breakout cable (40G QSFP+ to 4x10G SFP+), in the following configuration:

      -1Mellanox NIC (FCBT) in serverA is connected to 4 intel NIC (SFP+) in server B, using a breakout cable.

      But when we connect the breakout cable, just one 10G SFP+ is working from total of four, and 3x10G SFP+ is off (no light). We then generate the traffic, it is normal that just 10G traffic was passed.

      I think that this is due to the fact that Mellanox NIC is configured for 40G.

      My question is how can i configure Mellanox to recognize 4x10G configuration for breakout scheme?


      We tested this issue using Cisco switch configured to 4x10G SFP+ both breakout cable and switch ports were active and working.

      Thanks for your support