Unable to activate switch-to-switch operation with SFP functionality.
Unable to activate switch-to-switch operation with SFP functionality.
Here’s a revised version of your message:
So my configuration looks like this: A Cisco Catalyst 3750G connects to a Cisco SG350-52P. Both sides use 1.25Gb SFP LC modules, with a lengthy 12-strand fiber link—possibly around 300 meters—running between them. From each end, OM4 LC cables enter the fiber ports on the switches. The connection was functioning for about a day before it dropped, and I can’t get it back up. When it worked, I had full gigabit LAN access. I’ve tried different SFP LC modules for the switches, but nothing’s resolved. My next plan is to replace the LC cables entirely. I checked the ends of the cables with my phone camera; I see a laser coming through clearly. Could anyone offer advice or point out something I’m missing?
Side note: I didn’t install the fiber myself, but the setup seems correct—laser from the main switch down the same side as the second switch’s output. I’m pretty sure that’s the issue, so I swapped the fiber lines around. Now the laser is on one side and the second switch sends its beam from the other. Hopefully this fixes it. Thanks for your help!
When the mentioned laser hits the same fiber, it might affect the SFP unintentionally. This could have caused damage to the SFP, reducing its performance beyond a certain range.
I'm checking if the distance might be the problem. I've been using multi-mode SX SFP modules with OM4 cables in the switches. Now I've ordered single-mode LX SFP modules and OS2 single-mode cables. They're rated for 10Km, so I'm hoping it will work. The only info I have is that the fiber is 12 strands; let me know if you need anything else.
This occurs only after initiating 20km SFPs spaced a few meters apart.
I swapped the new SFP units on both ends but the problem persists. I’ll try the LX single-mode ones arriving Monday.
End the cables and rearrange them. This process won't harm anything.