Cisco WS-C3560CX and Single Mode Fibre Issue

[Juniper761]

Hi

Currently migrating some Catalyst 3560CX PC-S switches from Multimode fibre over to a new Single Mode OS2 fibre backbone

I’ve changed the SFP’s over to GLC-LH-SMD and cannot get the trunks to connect, they simply say notconnect and never illuminate

I’ve tested the fibre ports with existing connections over the same single mode and they work without issue so the fibre between the buildings appears to be good

Finally if I connect the switches directly from SFP to SFP with a fibre patch lead, eliminating the single mode fibre, the connection comes straight up

Has anyone any ideas what I’m missing please?!

[Marvin Rhoads]

Since you have -SMD type transceivers, they support DOM (Digital Optical Monitoring). So you can use the command:

show interface <int number> transceiver details

...to check on transmit and receive light levels.

I assume you've checked the most common issue - reversing polarity (tx vs rx) at the patch panel. If you haven't, please check that also.

[Leo Laohoo]

1. Are both ends using optics with the same wavelength, i. e.  SM?
2. What is the total distance of the link?
3. What type of patch cord is used? 
4. Did anyone shine a visible fault locator (VFL) down each end?

[marce1000]

         - Disable auto negotiation on the involved ports (at both ends)

 M.