No link with Connext X3 / Debian 10

Hi there, we have no connection with a connectX-3. No lights nothing. The card is found and the driver is installed. I´ve tried it with many cables, switches etc. All components are 10G. The cable is also shown in the compability list.

lspci | grep Mellanox

04:00.0 Ethernet controller: Mellanox Technologies MT27500 Family [ConnectX-3]

mst status

MST modules:

MST PCI module loaded

MST PCI configuration module loaded

MST devices:

/dev/mst/mt4099_pciconf0 - PCI configuration cycles access.

domain:bus:dev.fn=0000:04:00.0 addr.reg=88 data.reg=92 cr_bar.gw_offset=-1

Chip revision is: 01

/dev/mst/mt4099_pci_cr0 - PCI direct access.

domain:bus:dev.fn=0000:04:00.0 bar=0x93900000 size=0x100000

Chip revision is: 01

ethtool eno49

Settings for eno49:

Supported ports: [ FIBRE ]

Supported link modes: 1000baseKX/Full







Supported pause frame use: Symmetric Receive-only

Supports auto-negotiation: Yes

Supported FEC modes: Not reported

Advertised link modes: 1000baseKX/Full





Advertised pause frame use: Symmetric

Advertised auto-negotiation: Yes

Advertised FEC modes: Not reported

Speed: Unknown!

Duplex: Unknown! (255)



Transceiver: internal

Auto-negotiation: off

Supports Wake-on: d

Wake-on: d

Current message level: 0x00000014 (20)

link ifdown

Link detected: no

It´s only a single port ethernet card with 10G but there a 2 ports… The newest firmware is installed.

Anyone an idea?


Hello Hermann,

Thank you for posting your question on the Mellanox Community.

We have a few questions to better understand the issue you are experiencing.

  1. Which version of the Mellanox OFED are you using? You can see the version installed with ofed_info -s
  2. What is the model number for the cable you are using?
  3. What is the topology of your setup? For example connected to a switch or back-to-back
  4. If you are using a switch what is the switch model number
  5. What model of adapter are you using? You can get this from the output of lspci -vvv and looking for the line “[V2] Vendor specific
  6. What command are you using to bring up the interface? Please provide the output of this command.
  7. When you attempt to bring up the interface do you see any output in dmesg?
  8. Since you are trying to run at 10Gb you could test forcing the adapter to run at this speed. See the following article on the topic:

For example ethtool -s eno49 speed 10000 autoneg off

Thanks and regards,

~Mellanox Technical Support