On a C3750 switch I have an interface with
1000BaseLX SFP which is generating syslog error messages indicating the receive error threshold of -19dBm has been exceeded, the avg power level is now -21.1 dBm. A few questions (1) What CLI command do I use to generate this power level statistic so I can compare other interfaces (2) given these levels are measured in microwatts, how significant is this error? Thanks
The LX SFP has a minimum optical receive level of -20dBm. If your actual receive level is -21.3dBm, then you are operating below the minimum receive level for the SFP and you run the risk of increasing your bit error rate on the link.
You can check the Optical Receive Power level using the show interfaces interface-id transceiver detail command. Details are located within the following document.
Show Interfaces Transceivers