Port splitting (100G to 4x25G) support on ConnectX-5 MCX516A-CDAT

Hi all,

I am trying to use a 100GbE to 4x25GbE breakout cable with a ConnectX-5. My goal is to configure the NIC to treat a single 100G port as four separate 25G logical interfaces.

Is this hardware capable of port-splitting? If so, what are the mlxconfig commands needed to enable it?

Device Info:

  • NIC: ConnectX-5 Ex EN (MCX516A-CDA)

  • OS: Ubuntu 22.04.5 LTS

mlxconfig -d 0000:01:00.0 query

Device #1:

Device type:        ConnectX5
Name:               MCX516A-CDA_Ax_Bx
Description:        ConnectX-5 Ex EN network interface card; 100GbE dual-port QSFP28; PCIe4.0 x16; tall bracket; ROHS R6
Device:             0000:01:00.0

All thoughts are appreciated.

Hello Suraj_Chalapathy,

Thank you for posting your inquiry to the NVIDIA Developer Forums.

Unfortunately, split mode configuration is not supported on the adapter.

Those breakout cables are intended for use with switches - example, splitting out a single 100gbps switch port into 4x25gbps links towards the hosts.

Best regards,
NVIDIA Enterprise Experience