BiDi SFP on CRS326-24G-2S+: light but no link

Hardware MikroTik hardware general
1

Hi,

I’m new to the Mikrotik hardware, so my apologies if this has been answered before (I searched the forum and wiki, but found no solution).

I inserted two SFP modules in my Mikrotik CRS326-24G-2S+, and SwOS 2.9 reports that it sees light (about -6 dBm, which seems fine), but the link remains down. I plugged the same optics and same fibers in a Netgear SFP port (non-SPF+), and the links came up immediately.

Should I perhaps set the link speed to 1G somewhere (they are SFP optics in a SPF+ port), or did I buy incompatible optics somehow?
The optics are FS.com optics (with FS as vendor type in the EEPROM, correctly recognized by the Mikrotik), one SPF module a 1G BiDi 1490/1310 and the other SPF module a 1G BiDi 1310/1490 optic.

Would RouterOS give any different results (I have a CRS series, but as I only need switching functionality, I booted to SwOS)?

The Mikrotik SFP compatibility chart does not list non-Mikrotik brands, but FS.com list Mikrotik in their compatibility chart for this optic, so I assume Mikrotik does not have vendor-locking.

Edit: when I plug in a 1G multimode optic (1Gbase-SX) from FS.com, the link comes up fine, so this issue seems related to this type of optic (bidi, with both transmit and receive over a simplex fiber). Mikrotik does have a 10G BiDi optic (S+2332LC10D), but I can’t find a 1G bidi optic. Would the media type matter for optics support?

Any advice is much appreciated.

2

Yes, you have to set the interface manually to 1G (auto-negotiation off, 1G, full duplex). It’s written in the wiki in the same article you linked.
Mikrotik does have 1.25G BiDi optics but in 1310/1550 configuration as opposed to the kind you have.
Hope that helps.

3

Thanks, I solved my problem by turning auto negotiation off, and setting the link capacity to 1G fixed.

4

As always. Maybe Mikrotik will implement a extra button in ROS in that screen with the text “Does not work” and pressing it will disable auto negotiation for you.
Or make the default negotiation state being off.