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New Member

3750G and 2955C connected over MM Fiber?

Greetings,

I have a 3750G switch port cabled to a 2955C switch with multimode fiber. At the moment I have a SFP of type GLC-SX-MM in the SFP port on the 3750G.

The fiber port on the 2955C is labelled 100FX MM.

When I have the 2 connected over the fiber, I get no link LED on either end.

I suspect that the GLC-SX-MM (being Gigabit only) and the 100FX port are not able to communicate due to the speed difference. Is that correct? Do I need to replace the GLC-SX-MM with a GLC-FE-100FX to get link?

3 REPLIES
New Member

Re: 3750G and 2955C connected over MM Fiber?

Hi Charlie,

can you configure both the end for the speed of 100Mbps with "speed" interface command and check.

Regards.

Senthil.

New Member

Re: 3750G and 2955C connected over MM Fiber?

Only the Copper SFP allows you to set the interface speed or to Auto-negotiate

The gig fiber SFP's support only Gig. I'm not sure if there are any Cisco SFP's that do 100 meg.

Vernon

New Member

Re: 3750G and 2955C connected over MM Fiber?

Hello friend, remembers that single modules SFP GLC-SX-MM work on 1000mbps single in multiway and the fiber does not negotiate speeds, the only thing that you can make have a pair of equal modules in the ends or is GLC-FE-100X or GLC-SX-MM thus to be able to communicate them

note:both modules must handle he himself type of signaling MM or SM

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