c6500 Low alarms on optics

[James Lasky]

I saw some (--) low alarms on my optics.

I'm wondering if these alarms can cause any kind of problem.

Has anyone experience ?

Tks

#sh inter transceiver

Transceiver monitoring is disabled for all interfaces.

If device is externally calibrated, only calibrated values are printed.

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

NA or N/A: not applicable, Tx: transmit, Rx: receive.

mA: milliamperes, dBm: decibels (milliwatts).

                                         Optical   Optical

            Temperature  Voltage  Current   Tx Power  Rx Power

Port        (Celsius)    (Volts)  (mA)      (dBm)     (dBm)

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

Te1/4         33.1       0.00      31.1      -2.2      -0.7  

Te1/6         35.9       0.00      37.5      -2.1      -1.3  

Te1/7         36.0       0.00      38.7      -2.1      -1.7  

Te2/4         30.4       0.00      33.0      -2.1      -1.8  

Te2/6         33.7       0.00      37.6      -2.1      -1.8  

Te2/7         32.7       0.00      37.8      -2.5      -1.8  

Te3/2         33.4       0.00       8.7 --   -2.1      -3.0  

Te3/7         35.7       0.00      37.8      -2.4      -2.0  

Te3/8         30.8       0.00      30.7      -2.5      -1.1  

Te4/2         32.6       0.00       8.0 --   -2.7      -8.2  

Te4/7         29.2       0.00       6.8 --   -2.9      -3.2  

Te4/8         27.3       0.00       5.6 --   -2.8      -7.2  

Te7/1         38.2       0.00       7.2 --   -3.8      -1.8  

Te7/2         37.5       0.00       7.1 --   -3.7      -4.7  

Te7/5         31.9       0.00      37.3      -2.3      -1.9  

Te7/9         28.0       0.00      35.2      -2.0      -1.0  

Te7/10        27.7       0.00      38.1      -2.1      -1.1  

Te7/12        29.7       0.00       6.0 --   -2.1      -3.2  

Te7/13        28.0       0.00       5.9 --   -2.5      -4.6  

Te7/16        27.6       0.00       5.7 --   -1.8      -2.1 

[Bhishma Khanna]

Hi,

Low power alarms on transceiver suggests that the minimum threshold of signals which should be running in the transceiver is not meeting.

I would suggest you to just check the other end of these transceivers if they are connected to an operational device or not.

We may get these alarms if an unused transceiver is connected to the switch.

If the above situation is not with your case then please attach the "show version" and "show log" outputs.

It could also be a bad fiber or SFP due to which these alarms are generated because any layer one problem may also lead to the signal threshold not meeting.

So putting all together, there could be these three situations, unused transceiver OR a software bug OR layer one issue.

Hope this would help.

Thanks.

[James Lasky]

On the opposite side of the tranceivers there are some firewall, I'm not sure there is the possibility to check via cli.

Can these "problem" cause sometimes a problem ?

I'm mean sometime in some particular situation (that I don't know what could be), traffic is disrupted ?

Tks

[Bhishma Khanna]

Hi,

No, it would not cause any problem in the normal traffic flow because these are not errors but informational messages.It is just saying that the minimum electrical flow is not met which could be due unused SFP connection.

Thnaks.