Hi,

We are testing the new MikroTik CRS317-1G-16S+RM switch and are having an issue with the fan speed. It should be silent up until 40C but the fan speed appears to go up to 100% on both fans when the switch has booted. When checking the System > Health tab the info displays:

Temperature 1188 C
CPU Temperature 28 C
Fan Speed 13155 RPM
Fan2 Speed 13050 RPM
PSU1 State ok
PSU2 State ok

Normally i would say this is a faulty temperature sensor / reading, but we have multiple devices and as of now, 2 already show the same characteristics.

Happened on v6.40.2 and also on the latest v6.40.3

Anyone experiencing the same issues?

Small update, found out it happens when we plug a transceiver in. It appears the switch can't read the DOM info correctly.

Working with MikroTik and manufacturer now to solve this.

Update, we've been talking with the Mikrotik engineers and the transceiver manufacturer, turns out the firmware did not support the way the DOM needed to be read in the transceiver (internally calibrated as described in SFF-8472) and Mikrotik will add this in the next version 6.41 which will come out in a few days.

Should fix the fans spinning up to full speed!

Just tested the latest v6.41rc31 release candidante firmware and the issue has been fixed!

*) sfp - fixed temperature readings for various SFP modules;

We found the correct specification and many thanks to Mikrotik support for the very fast support!

I have inserted just DAC Cable from MT.
I am using SwitchOS and the fans are going at full speed.
Didnt try with RouterOS because I dont need it.

Is it planned to be fixed in the next SwOS ?

CRS317 fan support is added starting from SwOS v2.5.

Perfect.
I have the 2.5 and CPU temperature is 31° but the fan are running at full speed.

When do you plan to fix that? thank you

Hi,

The problem wasn't in the CPU temp, the problem was in the transceiver temp reading, what does it read in the GUI? (It appears above the CPU temp reading when a transceiver is inserted, or when viewing the properties of a specific port)

The SFP DAC from MT reads 101 °C

There is your problem, have you tried the latest release candidate firmware? (RouterOS)

No, I am just using Switch OS because on this switch I dont need any routeros features. Just a plain L2 10G switch needed here.
I have put 2.6 but the problem remains.

Alright we will contact the Mikrotik engineer and ask them when the fixes will be available in SwitchOS.

MikroTik engineers replied the fixes will be added in the next SwitchOS release, no ETA yet.

When will it be fixed in switchos? The fan is going off and on every few seconds. If the temparature on a SCP module reaches 40° ist goes on and if it goes down to 39.9° the fan goes off - and so on. I think that reduces the lifetime of the fan dramatically!

routerboard: yes
model: CRS317-1G-16S+
firmware-type: dx3230L
factory-firmware: 3.40
current-firmware: 6.41
upgrade-firmware: 6.41

temperature: 8C
cpu-temperature: 7C
psu1-state: ok
psu2-state: fail
fan1-speed: 6195RPM
fan2-speed: 6120RPM

..??

My CRS317 under Swos appears to be reading the temp of my Finisars accurately at 40C.

Problem is CPU is at 35C, but because my finisars are at 40C, the fans are kicking on.

Why is th efan trigger so low? The specified temperature range on these transducers is -5C to 70C. Seems silly to kick the fans on at 40C if they can go all the way up to 70...

Would be nice if this behaviour were configurable. If you could set your own target temp.

Finally I switched to RouterOS even If I dont need any routing features.
Even the latest release of Sw OS isnt perfect and the fan issue has not been resolved.

On CRS326, the switch hangs with SWos and works perfectly with RoS.