Mikrotik and Mellanox QSFP cable

RouterOS General
1

Hi.

I am trying to connect a Mellanox QSFP cable to my CRS518-16XS-2XQ running 7.11.2 (stable)

The switch discovers the cable as Mellanox MCP1600-E002 for a few seconds, then it disappears and comes back for a few seconds. So the link never comes up.

I have made a short video of what is happening if that can give any clue of what is going on:
https://youtu.be/3ZEvKHaRWyw

If there are any settings I can set to make the module stay present, please let me know!!

/Martin

2

Any reason not to upgrade your CRS to ROS version 7.16.2 ?

3

Not really, do you think that will solve the issue?

Will give it a try later in the evening, to see if this makes any changes.

4

I’m using a Mellanox MCP1600-E002 here between a CRS504-4XQ-IN and a Mellanox ConnectX-4. The only thing I did need to change was fec-mode=fec91, since then its working like a charm, no hiccups whatsoever, on 7.16.1 that is.

best

5

I have upgraded to 7.16.2 (stable), tried to change the setting to fec91, but unfortunately it does not make ane change. The cable keeps switching between “no link” and “initializing”

I have two Cisco UCS C240 M4 servers each with a HP 4x25G NIC, if I connect the cable directly between the servers. All links comes up. So the issue much be at the Mikrotik level.

Any help is much appreciated.

/Martin

6

Try disable auto-negotiation and set link speed manually, maybe that helps.

7

Still no luck. I think I give up and will be replacing the switch With something else. If anyone is interested I will be putting the switch up on eBay on a couple of weeks when the replacement switch is in place.

8

Well, there is still the option to post your config here, maybe something clearly off can be spotted.
As a final resort, you should open a support ticket with Mikrotik, maybe they can help, also that’s what everyone after you running into the same problem will be very happy about.

Your choice (;

9

Or, cheaper than throwing away 1,5k€ (it will end up as a keeper unless you offer it as an 1€ auction anyways): write to Mikrotik support and ask about the compatibility. You cant expect in a community forum to have the solution after one single day. https://help.mikrotik.com/servicedesk/servicedesk

Deal?