M2S250-48LP SFP ports on front - usable with stacking?

[GavinMcMenemy]

We've got 2 MS250-48LP that are currently stacked. These need to patch to a fibre panel. We've plugged in a Meraki SFP module into front ports but we don't get any signal . I've been reading the docs and I don't see anything that says if the stacking cables are in use then we can't use the fibre ports on the front.

But maybe I've missed something? 

[alemabrahao]

Yes, you can use the front SFP ports even when stacking is active. The stacking ports are separate QSFP interfaces on the back of the switch and do not disable the front SFP ports.

What sfp model are you using?

[GavinMcMenemy]

The part number I have is: GLC-SX-MMD

Which I believe is this: https://networkwarehouse.co.uk/products/cisco-refresh-sfp-gigabit-transceiver-module-1000base-sx-glc...

And if that is the case should be usable?

[alemabrahao]

It should work without problems, what you can do in this case is try to invert the fiber wires (TX/RX), check on the Meraki panel if the SFP was detected correctly, try another module or GLC-SX-MMD port or confirm if the type of fiber used is multimode (OM1/OM2/OM3).

[GavinMcMenemy]

The fibre is OM4 bought in the same batch as others used in patching in our MX (so using the same SFP modules). This is a new office and we're finding it difficult to get access to comms and distribution cabs ahead of time but I'll talk to management. 

Already tried swapping around the different modules and SFP ports. and also plugging in to different ports in different switches.

I'll report back with more details once I get in.

[alemabrahao]

But on the dashboard, can you check if the SFP was recognized?

[GavinMcMenemy]

Oh actually. Good point.

[GavinMcMenemy]

This is all I'm seeing on the switch sfp port just now. There's also a DOM warning but I think that's because the cable isn't plugged in. 

From what I can tell this should also be compatible with the SFP port on our MX85. When I check the MX I'm not seeing anything in either SFP port to tell me there's a module plugged in and I can't remember how it's been left.. Maybe the issue is there. It'll have to wait now until I can get access to the comms cabs.

[alemabrahao]

Everything seems to be working properly on the switch.

Can you test this SFP on a device other than the MX85? Perhaps another switch.

[GavinMcMenemy · Accepted solution]

I'll tell you this. It's a weird one. Came back to the cabinet. Plugged in the cables and prepared to do some troubleshooting and ... this time it worked. Same cables, same laptop, same RJ45 into the switch. SAME EVERYTHING. 

And this time it worked. 

Going to chalk this up to "one of those things"

[PhilipDAth]

If you have plugged it into an SFP WAN port, it only activates those on boot.

[GavinMcMenemy]

No, it's in port 13, that's not WAN. We did reboot it at the time anyway.

[alemabrahao]

Take a look at the list of SFPs supported by this switch model.

https://documentation.meraki.com/General_Administration/Cross-Platform_Content/Small-Form_Factor_Plu...