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Community Member

3560 SFP Troubles

I am trying to connect 2 3560's via the SFP ports and I am only getting link light on one end and only one switch shows connected with an active trunk. The other switch sees the module but will not recognize the trunk and never does show connected or link.

The SFP's that I have tried are GLC-SX-MM and SFP-GE-S. The distance between the buildings is less that 500ft.

I am on 850-nm Fiber between buildings and it is currently working with a 6509 and a 4006. If I feed out of a gbic on the 6509, I get the same thing when attaching to the 3560.

Any help would be greatly appreciated,


Community Member

Re: 3560 SFP Troubles

Check your console for this message:

%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port Gi#/#/## has bad crc

Thats what it was in my case...

Re: 3560 SFP Troubles


As other poster mentioned do check out the logs in your switch to have more info on the kinda problem you are facing with and also the reason for the same.


Community Member

Re: 3560 SFP Troubles

I have checked the logs and did not have any errors, I looked at that prior to posting. However, the problem is resolved, come to find out I had some bad fiber between buildings.

Thanks for the replies and help.

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