SFF8472-5-THRESHOLD_VIOLATION

[Mukund M Deshpande]

Hi every one !

getting error on my switch -

Aug 19 19:50:24: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm. (SW-2)

Aug 19 19:55:05: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm.

Aug 19 20:00:24: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm. (SW-2)

Aug 19 20:05:05: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm.

Aug 19 20:10:24: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm. (SW-2)

Aug 19 20:15:05: %SFF8472-5-THRESHOLD_VIOLATION: Te2/1/1: Rx power high warning; Operating value:  -0.1 dBm, Threshold value:  -1.0 dBm.

switch -

WS-C3750X-48T-S

IOS -

c3750e-universalk9-mz.122-55.SE6.bin

SW#show int te2/1/1 transceiver detail

ITU Channel not available (Wavelength not available),

Transceiver is internally calibrated.

mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable.

++ : high alarm, +  : high warning, -  : low warning, -- : low alarm.

A2D readouts (if they differ), are reported in parentheses.

The threshold values are calibrated.

                              High Alarm  High Warn  Low Warn   Low Alarm

          Temperature         Threshold   Threshold  Threshold  Threshold

Port       (Celsius)          (Celsius)   (Celsius)  (Celsius)  (Celsius)

--------- ------------------  ----------  ---------  ---------  ---------

Te2/1/1     26.6                75.0        70.0         0.0       -5.0

                              High Alarm  High Warn  Low Warn   Low Alarm

           Voltage            Threshold   Threshold  Threshold  Threshold

Port       (Volts)            (Volts)     (Volts)    (Volts)    (Volts)

---------  ---------------    ----------  ---------  ---------  ---------

Te2/1/1    3.29                  3.63        3.46        3.13       2.97

           Optical            High Alarm  High Warn  Low Warn   Low Alarm

           Transmit Power     Threshold   Threshold  Threshold  Threshold

Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)

---------  -----------------  ----------  ---------  ---------  ---------

Te2/1/1     -2.6                 1.7        -1.3        -7.3      -11.3

           Optical            High Alarm  High Warn  Low Warn   Low Alarm

           Receive Power      Threshold   Threshold  Threshold  Threshold

Port       (dBm)              (dBm)       (dBm)      (dBm)      (dBm)

-------    -----------------  ----------  ---------  ---------  ---------

Te2/1/1     -2.6                 2.0        -1.0        -9.9      -13.9

What could be the issue , is there any workaround  .

Thank you .

[Marvin Rhoads]

The log messages indicate Rx optical power is too high (-0.1 dBm). The "show..." output indicates Rx optical power of -2.6 dBm (within specification).

Was that show command run at the same time as the log messages were coming in? I ask because they don't seem to match. Normally I would not expect see such a high Rx optical power unless you were using laser-driven (singlemode) transceivers with extremely short distances (e.g. back to back) or possibly a loopback jumper.

What is the transceiver type and how long is the span? What does the distant end indicate its optical transmit power to be?

[Mukund M Deshpande]

Hi Marvin ,

Thanks 4 ur reply .

This fiber used to connect HP server in same lan .

show int te2/1/1 transceiver detail command output not taken at same time when we saw the issue .

logs are coming and going again n again and its there sinc more then a month back .

I yet to get the info on HP server end transmit power , transceiver  type is - "SFP-10GBase-SR "

waiting for your reply .

Thank you

[Vignesh Rajendran Praveen]

Hi Sagar,

I see that the message is a level 5 message and it should not cause any disruption to your connectivity, it's informational. Rx power high alarm message is generated when the Optical Received Power is above 0.5 dbm or when the monitoring done by on-transceiver hardware is not reading the values properly. Also, this is just a high warning and not a high alarm. So,it shouldn't impact the real time traffic.

Having said that, still the reason for the error message could be due to one of the following:

1)    Bad fiber

2)    Bad transceiver module

I would strongly recommend the following action plan.

1)  Replace the fiber link. This means doing all possibilities of swapping(includes swapping the cables from Tx to Rx, etc) on the complete fiber path(switch---- patch panel ---- destination end). Basically, we will have to do a complete physical layer testing.

By doing a complete testing of this fiber link, the warning should stop occurring. Therefore, I would suggest this to be our immediate action plan.

2) Then we can try to reseat the transceiver module on both side .

3) If it doesn't resolve the problem then we can replace both side transceivers. 

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Thanks & Regards,

Vignesh R P