power low alarm on c3750x stack switch

[pradip.saha]

In one of my customer's newly installaed setup I am getting below message in one of the c3750x stack switch.

Mar 31 06:02:54.875: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/1/1: Rx power low alarm; Operating value: -26.8 dBm, Threshold value: -21.0 dBm

Mar 31 06:02:55.135: %SFF8472-5-THRESHOLD_VIOLATION: Gi1/1/2: Rx power low alarm; Operating value: -26.0 dBm, Threshold value: -21.0 dBm

Mar 31 06:02:57.392: %SFF8472-5-THRESHOLD_VIOLATION: Gi2/1/1: Rx power low alarm; Operating value: -27.4 dBm, Threshold value: -21.0 dBm.

Mar 31 06:02:57.669: %SFF8472-5-THRESHOLD_VIOLATION: Gi2/1/2: Rx power low alarm; Operating value: -26.6 dBm, Threshold value: -21.0 dBm.

Pls. have a look and suggest me on how to resolve the issue.

Thanks in advace.

[Leo Laohoo]

What SFP modules are being used. 

Start by cleaning the fibre optic patch cable ends.  

[pradip.saha]

Hi Leo,

SFP modules used are

CISCO GLD-1000 Base-SXSFP-MMD Gibic (PN: 10-2626-01)

There is no fiber optic patch cable connected now. Only SFP's are connected.

Hi Leo,

New update here. Currently we have connected 2 fiber patch cords at port Gi1/1/1 and Gi2/1/1. Now we are not facing the message for these two ports.

But getting the message for ports (Gi1/1/2 and Gi2/1/2) where Gig module is inserted but no fibre patch cord terminated (Gi1/1/2 and Gi2/1/2).

Pls. advise.... and let me know the cause of the issue.

Thanks in advance.

[Zach S]

Pradip,

If you aren't using those ports, then putting them in disable state, with "shutdown", should cause the alarm to stop popping up.

[pradip.saha]

Hi, Yes I have kept those unused ports in dasiabl mode with "shutdown". Now the message is not coming.

So, finally if the ports are connected through Fiber optic patch cord and if the unused ports are "shutdown" then the message is not coming.  But I want to know why the message is coming in normal condition ? what is the cause of the problem ? Is it normal or any bug ? Pls. response urgently.

[Zach S]

Pradip,

This isn't really a problem, if you don't have anything connected. It's just an error telling you that the fiber optic port isn't receiving much of a signal. If you have a fiber connected and you get this error, that means an insufficient amount of light is being received on that port. Insufficient rx signal can mean you have a broken fiber, your transmit port on the the other end isn't working correctly, or many other root causes.

In your case you had nothing connected, and since the ports are enabled they expect to receive signal, but receive nothing, causing your error.

So nothing is really wrong with your switches.

[pradip.saha]

Hi,

Thanks for yoursupport.

[rosaho]

This discussion has been reposted from Additional Communities to the Optical Networking community.