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Ethernet Switches & Routers

Occasional Contributor
Posts: 7
Registered: ‎01-10-2012

FCX Temperature Reading Inquiry

Greetings!  I have an FCX648-HSPOE with a fan that is acting a little squirrely repeatedly switching the fan speed from 1 to 2 and back over and over...We have ruled out any environmental issues, AC/cooling is good, airflow in and around the rack is nornal, and power is normal. The <sh chassis> command shows me that the temperature readings (even when fluctuating) are falling below my thresh hold settings, and I have compared everything to a couple of our other devices we have in the same rack which are issue free - so essentiall, everything looks normal. Before I open a case with Brocade support I was hoping someone could clarify what exactly 'MAC temperature' is referring to in the <sh chassis> output?! The CPU temp is obvious, but I cannot find any reference to what the MAC temp specifically gauges? A couple of the config guids, installation guides, and some internet searching do not pull up anything specific either (although I am guessing it is either 'memory temperature' or 'voltage temperature'. Any ideas are greatly appreciated!!


MAC 1 Temperature Readings:

        Current temperature : 53.5 deg-C

MAC 2 Temperature Readings:

        Current temperature : 60.5 deg-C

CPU Temperature Readings:

        Current temperature : 47.0 deg-C

        Warning level.......: 85.0 deg-C

        Shutdown level......: 90.0 deg-C





Occasional Contributor
Posts: 7
Registered: ‎01-10-2012

Re: FCX Temperature Reading Inquiry

Update - I contacted Brocade Tech Support and they were unable to tell me what the MAC temperature referred to beyond 'an internal temperature indication'. I actually have access to a Brocade 'Premier Plus' support engineer and he indicated that it refers to air flow 'zones' (input/output) in the devices and changes per the device family.  I have never read that in any of the Brocade literature - and would love a MORE specific indicator!


*You specifically referenced a MAC 'chip' - that adds another target: CPU, MAC chip, air flow zones, 'memory'....

Frequent Contributor
Posts: 160
Registered: ‎08-07-2009

Re: FCX Temperature Reading Inquiry

Hi Thomas,


Im not exactly sure what the exact reference is here. It could be the ASIC on board or could be a sensor on the MAC chip. Let me check with someone in engineering and try to get an answer for you.



New Contributor
Posts: 4
Registered: ‎03-13-2012

Re: FCX Temperature Reading Inquiry

I was just wondering if this has been answered.  I have several FCX stacks and a few stand alone FCX,  I notice this same behavior only on the stacks that have 7400 firmware.  I have rolled back a couple of stacks to an older firmware (7202e) so my log doesn't fill up in a day or two with automatic fan changing back and forth. 

Occasional Contributor
Posts: 12
Registered: ‎10-29-2014

Re: FCX Temperature Reading Inquiry

You can remove the logging for these events by adding the following line in the global config


no logging enable fan-speed-change



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