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Cisco SFP GLC-LH-SM unknown in show interface status

blue phoenix
Level 1
Level 1

Hi all,


Client installed a single mode fibre run from Distribution Switch to Access switch. The distance is not even greater than 100 Metres but the client insisted since the fibre is free.

On the Cisco Catalyst 2960X-24TS-L (Access layer not stacked) the SFP is identified, but on the Cisco Catalyst 2960X-24TS-L (Distribution switch stacked) the SFP module is "unknown".

Gi1/0/49 access_sw po notconnect 1 auto auto 1000BaseLX SFP

Gi1/0/49 dist_sw po notconnect 1 auto auto unknown

Distribution switch is running 150-2.EX4
Access switch is running 150-2.EX5

I have configured on both sides speed nonegotiate, above output is showing that the 2 are not even talking to each other since their status is still auto auto...

Any ideas is gladly appreciated in terms of what show commands or diagnostic tests I can do for the interface just to test it?

I have tried to test it but it is saying diagnostic monitoring is not running, how can I run that feature as well?  Is that network impacting if I did?

Kind regards,

2 Replies 2

Reza Sharifi
Hall of Fame
Hall of Fame


Is there a link light on either side of the connection?

Is the SFP on the distro switch also LX?

If there is no link light, try crossing the strands on one side of the connection and test again.




HW fault on the module itself...

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