SX6025 and QSFP-LR4-40G


we have multiple SX6025 switches and want to connect them within 2 different rooms.

We bought 4 QSFP-LR4-40G modules LC/LC 1310.

If we connect them to the switches, we dont get a link status up and running.

Is this possible or do we use the wrong switches/interfaces?

Do we have to configure the opensm to accept 40Gbit interfaces?

Best regards,


Hi Volker,

Thank you for posting your question on the Mellanox Community.

Based on the information provided, the switch you are using is an unmanaged switch. Based on the supported InfiniBand speed, the switch will auto-negotiate the correct speed if the transceiver is supported.

Unfortunately, the transceiver you are using is Non-Mellanox transceiver, which we do not support as the transceiver is not tested by us in combination with the switch.

The supported and tested transceivers for this switch can be found through the following link →

If you experience new issues when using a supported Mellanox transceiver in the switch, please do not hesitate to open a Mellanox Support ticket through

Thanks and regards,

~Mellanox Technical Support

Any ideas? Do we have to configure link speed in opensm.conf or partitions.conf?

opensm.log didnt recognized that we pluged in a new interface and we got no link signal.