2960G SFP connector

Answered Question
Sep 14th, 2010
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I have 2 2960G ( WS-C2960G-24TC-L ) switches and a SFP cable with a part number of cab-sfp-50cm and what looks like a serial of YAAZ0034.  This cable came as part of the order.

Whenever I plug this cable into any 1 of the 4 SFP ports I get " %PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found "

I've tried 2 different ios images, c2960-lanbasek9-mz.122-53.SE2.bin and c2960-lanbasek9-mz.122-55.SE.bin with the same results.

My question is this: if the cable is bad, would I get a different message? Or, is this the message that applies to incompatible cables only?

Any help appreciated!

Correct Answer by Jerry Ye about 6 years 10 months ago

CAB-SFP-50CM is not supported on the 2960's.

Please find the SFP supports from the following link




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Overall Rating: 4 (2 ratings)
Tom Randstrom Tue, 09/14/2010 - 06:38
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The "%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found" error message is related to the SFP module you are plugging into the 2960.

What SFP are you trying to use?

What type of fiber are you trying to run these circuits over (what is installed in your facility).... 62.5 or 50 micron Multimode (MMF) or Singlemode (SMF) fiber?

The cab-sfp-50cm is a mode conditioning patchcord.  The 2960 cannot identify if you are using this or any other cable.  Only the system performance may be impacted.



mikeike808 Tue, 09/14/2010 - 08:05
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Thank you Jerry and Tom for the quick replies!

Jerry, that is a great link that I've stored.  Thank you.

Tom, I'm just trying to connect these 2 2960Gs together in a development lab that isn't even connected to the rest of the network, so the solution I'm hoping to find will be in the form of a single cable that the switches will recognize and use to communicate with one another.  The existing fibre cable we use is LC / LC Multimode Duplex 62.5/125 Fiber Optic. Looks like its been around a while, too: )

I didn't expect this to be so hard.  I actually called Cisco yesterday and was told that a WS-X3500-XL was what we needed.  I'm glad I've kept looking.

Thanks again, guys.  Take care!


Tom Randstrom Tue, 09/14/2010 - 09:17
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If it wasn't hard, then you wouldn't learn anything! :)

Just use the "GLC-SX-MM" SFP modules in your 2960G switches with your LC/LC Multimode Duplex 62.5/125 Fiber Optic jumper cable and you will be interconnected.

Good luck!


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