Fiber Part of my IP Cam Network Not Working


Jun 1, 2022
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Wilmington, DE
Instead of a network, I currently have a not-work...

I'm trying to set up an IP cam network and part of that network is to be extended to a detached building that will be connected via optical fiber.

I have the following hardware:
2 MikroTik RB260GS switches (firmware v 2.13), which includes an SFP port. All switch configurations are default settings.
SFP modules: HiFiber 1.25G Single Mode SFP LC Modules, 1000Base-LX/LH Fiber Transceiver
Cable: FiberCablesDirect OS2 LC LC Fiber Patch Cable | In/Outdoor Duplex 9/125 Singlemode

In my test setup, I have my PC connected to the first switch ( then to the second switch (
When the switches are connected via Ethernet and with the fiber disconnected, I can connect to each switch.
They both report the SFP module is part number "GLC-LH-SMD" and the type is "1310nm multi-mode fiber".
When I connect the switches with fiber and disconnect the Ethernet, either does not respond to pings (timeout) or once in a while a packet will get through.

Is the SFP module is incompatible (since it should be single mode but reports as multi-mode) or is there something else I should be looking for?


Staff member
Mar 10, 2014
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Hard to say what the problem is.

It could be that your switches are correct and the transceivers are actually designed for multi-mode fiber such that you have the wrong kind of cable for them. Common advice on the internet says it won't work with fiber and transceiver modes mismatched. Certainly you could expect some amount of compatibility despite this mismatch, particularly on shorter cables, but the signal strength is likely awful (could verify this via each switch's web interface perhaps).

It is also possible that some of the equipment is defective. Could be anything, and without extra hardware to swap, good luck figuring out what is wrong.

Still, maybe you can learn something from the info in the switch web interfaces. Here are screenshots from my switches so you can get an idea for what is fairly normal. Most of my fiber links are multi-mode using 10 Gbps SFP+ transceivers from Finisar which I got on ebay for about $6 each.

First the Errors tab. Most of my fiber links have a lot of Rx Pauses or Tx Pauses and these seem to be fairly normal and do not seem to greatly affect performance, at least not on the scale that I get them. All my other readings are either 0 or very low (these switches have almost a year of uptime).

(different switch)
(different switch)

And the SFP tab from each of those switches:


Here's some info from some other mikrotik switches at my brother's place. These are all 1-gigabit Ubiquiti transceivers in Mikrotik switches.

1655930227792.png 1655931161129.png 1655930236363.png 1655930243129.png 1655930248534.png