Hello,
I got the L009 (SFP 2.5G) & RB5009 (SFP+ 10G) as gifts and would appreciate any advice on what adapters to use to connect those two. The speeds that I am interested in for now is a 2.5G link between the two. Distance is roughly 50-60ft.
Would I need a SFP+ adapter for the RB and the SFP one for the L009? Most that I found seem to be for short distance as in interconnects in the same bay… thank you.
You need SFP+ modules for both sides (SFP without + only goes up to 1Gbps). You have a choice of using either ethernet cable (UTP cat7) or fiber optics (either multimode or singlemode would do), but ethernet is limited to 30m/90ft and even on shorter distances it tends to downrate link (2.5Gbps would probably work just fine) and RJ SFP+ modules tend to run hot. So if you have freedom, go with FO solution.
There are also AOCs, which are essentially pre-fabricated kits with FO modules and permanently attached FO cable, cut to certain length … Usually they’re made up to 5m in length, but 10m is not unheard of. But when routing the cable, you need to pull the module as well … so not suitable if space is tight.
In any case beware that RIS is a bit picky about supported SFP+ modules, with 7.13 MT introduced additional constraint on supported models so even modules which used to work before may not work any more. When buying, either have reseller guarantee that they work with ROS 7.13+ or have option to return them and get replaced with different type.
Thank you for the reply, The L009 page lists that it supports SFP only but with 2.5G speeds, what does that mean ? Or is it a mistake. If I understand your recommendation, the ideal solution is to have two SFP+ adapters with a FO cable (with connectors) that I can run between the two (50-60ft).
I found this Mikrotik help page where it also lists that the L009’s SFP can support 2.5G in forced mode if required???I also read that an SFP+ transceiver can not be plugged into an SFP port, otherwise, the product or port may be damaged!
Furthermore, this help page https://help.mikrotik.com/docs/display/UM/L009UiGS-RM mentions it supports SFP+.
In summary, it may be possible to run an SFP module at 2.5G speeds for very short distance on the L009, just noticed note 14 in the wired compatibility page for L009 that shows three compatible interfaces and all of them are max 3-5m under the 1G SFP table, but then the L009 also shows up under the 10G SFP+/25G SFP28 table. Darn, what does this L009 support in terms of FO transceivers?
I’d like to ask the same question quoted here.
I have one L009 and would like to connect it to my RB5009 over SFP. I earlier got the S+ RJ10 but they seemed to be incompatible with the L009 so I replaced them with a pair of S+85DLC03D. This as per the compatibility chart on Mikrotik docs should support 2.5G using “forced speed mode”. I just don’t understand how to use that mode. I tried setting auto negotiation off and set the rate to 2.5 Base X, even tried 2.5 Base T. neither seemed to work. Although they’re working fine when set to auto-negotiate and get a speed of 1G.
Can someone help with getting 2.5G here?
That device L009 has that note 14 plastered all over, but I could also not find any reference to “forced mode”, unless it means setting the interface to 2.5G. I didn’t buy the L009 for that reason & may resort to buying a 2nd RB5009 and use it as plain dum switch/bridge.
Exactly. I am going crazy looking for clear steps to do that. I hope someone here is able to help me out
Given you have both products and transceivers, did you try creating a support ticket? You can open a ticket at help.mikrotik.com or email support@mikrotik.com.
jfyi, I found this: https://wiki.mikrotik.com/wiki/MikroTik_wired_interface_compatibility#SFP+/SFP28_interface_compatibility_with_2.5G_transceivers. Is the command listed there the same as what you executed on both devices? In that same section, notice the reference to SFP+/SFP to RB5009/L009 respectively… I wonder if 2.5G is supported in L009 but only for short distances.
RB5009 series - SFP+ interface can be used in 2.5G mode if required.
L009 series - SFP interface can be used in 2.5G mode if required.
I contacted support & I am pleasantly surprised with their promptness & help. They said it should work, just to make sure to execute this command (similar to above link) to get 2.5G link working between RB5009 & L009 & as well use the transceivers you got.
/interface ethernet set sfp1 auto-negotiation=no speed=2.5G
It’d be very appreciated if you try & let me know as I am considering to purchase 2x of S+85DLC03D.
I have a L009. You can use SFP+ transceivers in forced 2.5G mode, or you can use 2.5G transceivers. They are rare, but they exist. I’ve used both a generic 2.5G base T (this one actually https://www.amazon.com/dp/B0BBV3KY59) and a generic 2.5G base X transceiver (this one https://planetechusa.com/product/mgb-2gsr-2-5g-sfp-transceiver-multi-mode-850nm-ddm-070c-300m/) and they both work as you’d expect them to, even with autonegotiation. Alternatively, all of Mikrotik’s transceivers work in forced speed mode.
Hi, thank you for confirming. I didn’t think for some silly reason I could use rj-45 SFP+ so I ordered the GTEK SFP+ w FO cable to run. I already have a cat6 cable wired between both ends, I’ll check the SFP+ rj-45 variant.
If you can, then it would still be better to use FO connection. RJ45 SFP+ modules tend to run pretty hot (depends on length of cable connection) which can be a problem in passively cooled devices such as L009 and RB5009. FO modules fare much better in this regard.
Thanks for the advice! I can and will, just a matter of running/routing the FO cable through, it’s some work but not hard. The distance is roughly 20m (65ft).
Experience (of other users on this forum) is that 20m of UTP cable is a practical limit for MT’s own S+RJ10 to reliably link at 10Gbps (specs say it’s 30m). And after that it automatically down-switches to 5Gbps or 2.5Gbps. Other vendors’ SFP+ RJ modules are not much better, the limit is always available power, copper requires quite some Tx power for 10Gbps. That’s why FO is much better.
Thanks to all the help here and from MK support, I got two 10Gtek 10GBase-SR SFP+ and OM3 LC-LC FO cable. Connected the L009 SFP port to RB5009 SPF+, then ran the above command (auto-negotiation off, 2.5G Base-X), and it all worked 
Funny how this command does not work (syntax error)
Any ideas?
Press TAB and you’ll see the list of possible values:
2.5G-baseT 100G-baseCR4 10G-baseSR-LR 1G-baseX 50G-baseSR2-LR2
2.5G-baseX 100G-baseSR2-LR2 10G-baseT 40G-baseCR4 200G-baseCR4
5G-baseT 100G-baseSR4-LR4 10M-baseT-full 40G-baseSR4-LR4 200G-baseSR4-LR4
25G-baseCR 100M-baseT-full 10M-baseT-half 50G-baseCR 400G-baseCR8
25G-baseSR-LR 100M-baseT-half 1G-baseT-full 50G-baseCR2 400G-baseSR8-LR8
100G-baseCR2 10G-baseCR 1G-baseT-half 50G-baseSR-LR
Any ideas?
Even two 
Both will tell you it should be
/interface ethernet set sfp1 auto-negotiation=no speed=2.5G-baseT
Most of the modules being discussed on this page are optical, it should be 2.5G-baseX.
Yes, you are correct. Thanks.
baseT for copper, baseX for optical
For DACs, both should work as long as configured the same on both ends.
While 2.5G optics exist, it is very rare so I wrongly automatically assumed copper.
2.5G RJ5 SFP does not exist on MikroTiks hardware site. S+RJ10 does not work with auto negotiation off and forced 2.5G speed in L009 SFP port. I’ve tried and this router did not like it. The result was that link kept connecting and disconnecting.. in a loop.
Without anything connected. No changes when I also tried connecting an ethernet cable to my CRS310 2.5G switch.
Have not tried a 2.5G SFP though I’ve seen them on eBay.
I really don’t know what transceivers MikroTik want us to use for the L009.