After a recent RouterOS version, a new feature was introduced to automatically disable SFP ports if the module is operating at >=95°C.
Obviously this is good default behavior, but is there a way to disable this feature on demand?
Some of our equipment are in deplorable places where we can’t solve for better cooling and have to operate it like that.
This feature is forcing us to keep using 6.47 instead of updating to 6.48.
Interesting. As another work-around, do you think these types of heatsinks on the SFP module would help?
i doubt it’d have much effect, as the temperature rises extremely quickly as soon as the interface is enabled and stays very high. there is no airflow in the places we have this issue, hence why heat spreaders would make little difference.
I would recommend (and MikroTik recommend this as well) to use some types of SFP only in devices that have an internal fan.
There are some devices that do not come with a fan but have the possibility to install it (there already is a cut-out and connection point).
This should force some air along the SFP and that will likely work better than a heatsink.
Just an update, apparently you can change the threshold via CLI
interface ethernet set sfp-shutdown-temperature
Heat management is a very complex topic, and most people’s intuitions on how heat flow works is wrong. Unless you have a strong physics background, you’re better off trying the experiment than speculating ahead of the data. Even an epoxied-on penny can be effective.
the temperature rises extremely quickly
Faster than a multi-core Intel x86-64 CPU? Ever tried to run one without a heat sink?
there is no airflow in the places we have this issue
Have you measured the air temperature inside the enclosure? Unless it’s the same as the SFP core temperature, there is heat flow, so a heat sink can be effective.
I noticed, that the SFP+ S+RJ10 modules stay a lot cooler, when they are operated at 1 Gbit/s speed. Would be very nice if Mikrotik first would degrade the connection to a lower speed before completly shutdown the module. The current shutdown threshold in ROS7 is 95 °C . So my workarround I probably try to implement is read out the SFP+ temperature from time to time, if higher than 90 °C, then degrade to 1 Gbit/s. Reset after 8h. In my setup, I only get the outage at some days in summer. For the rest of the year it is not near the threshold. With this method, I would at least be able to establish an admin connection and monitor the device instead of a complete blackout.
Does someone now how to implement that? - Tried to set the advertisement speed for the module and stop/start the connection. For some reasons, the connection stays at 10 Gbit/s.
Found an interesting solution using the 10Gtek immersion cooling components. They sell SFP+ extension cables, that came in handy.
I designed a cooling solution around it. The files for 3D-Printing and bill of material I published under: https://www.printables.com/model/896841-passive-sfp-module-cooler
