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SPF-10G-SR & X2-10GB-SR not able to commnucate

Level 1
Level 1

My Dell server is connected with SPF-10G-SR module using LC-SC OM3 MMF fibre optic cable connected to Cisco 3750E's X2-10GB-SR module. However when I run sh inventory command, it is showing the below message:


ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
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).



9 Replies 9

Leo Laohoo
Hall of Fame
Hall of Fame

Try reversing the polarity.

Hi Leo,

    I have reversed the fire optic cable at the switch but it doesn't work.

Loop the link around to determine which end is faulty.

How do I that?

X2-10GB-SR:  Connect the Tx strand into the Rx port of the same optic.  Does the link go up or not? 

SPF-10G-SR:  Same as above.  

Level 1
Level 1


I am having a similar issue where we are connecting switches in two racks close to each other on single mode fibre. The link does not come up on 10g-LR (assuming they are too powerful). Is there a 10G single mode SFP that is recommended for very short reach like inter/intra rack connection? 

I understand that 10G-LR is long reach but is there a short reach single mode?


Thanks in advance

@Ciscouser1! wrote:

two racks close to each other on single mode fibre

Not going to work.  

The power levels shouldn't be an issue. The max transmit power is 0.5dBm and the max receive power is 0.5dBm. Have you tried connecting the two fibers together at one end of the link and see if you get a signal back? Maybe a bad fiber jumper?




Make sure the 3750 runs at least IOS 12.2(35)SE2


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    When the mirror will then always repond to me with ' The only thing that exceeds your brilliance is your beauty! '