installing single mode fiber and switches not connecting

[witkopstaub]

This is my first use of 50u single mode fiber. Prior we only had 62.5u multimode. I've got 3750x switches and new SM SFP and yellow fiber patch cables. None of my links show connected. No lights and trunk port interfaces show down/down.

Is there a special command you have to do on a port when using SM fiber? Do you think I need cross over fibers?

Also, should I be able to see a laser signal light like MM or is SM a different frequency so it's not as visible as MM?

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[jyoung]

there is no special command for single mode on the switch and no, you cannot see SM light like you can MM. I would try a crossover fiber patch.

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[Alexander Maroukian]

Hi,

Connect them tx-rx -> rx-tx (crossover).

Best regards,

Alex

[witkopstaub]

Guess I was assuming the SFP would do the crossover automatically, like MDIX on a port. Does a MM SFP do this but not SM?

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[Alexander Maroukian]

Hi,

The rx/tx markings on the SFP then will not make sense then. Well there are modes when you use single strand.

What is the model of your SFP?

Best regards,

ALex

[jyoung]

no neither of them do.

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[Reza Sharifi]

If you are sure you have the correct optics, then you need to test your fiber with a fiber tester.

http://cableorganizer.com/ideal-industries/visual-fault-finder.htm

Don't look at the light directly. shine it to you hand or somewhere else.

also, mahe sure you are connecting the correct fiber patch.

if multimode, make sure you are using the same OM on both sides.

for example 50u-OM3 should connect to 50u-OM3 not OM2 or OM4

HTH

[flokki123]

hi robin,

you mentioned something with trunk, so i guess you are teaming two SFP´s to a trunk.

if so, resolve the trunk and try it with one SFP first, just to eliminate the possibility of a misconfiguration in the trunk settings.

Regards,

Florian

[pughaz1330]

Dear Team,

No need for any extra command for SM fiber and you can check the laster light signal visible

Thanks & Regards

D.Pugalendi. Senior Consultant (Networks), TAFE Ltd.,

35,Nungambakkam High Road, Chennai 34,Phone - 044-32977969 ; 9962017117