Hi all,
I was looking to get some info about adding a SFP-RJ45 module to the new hEX S (2025) which is capable of 2.5Gbit via SFP port.
As this router would need to be connected to another ethernet 2.5Gb I was looking at which module could be installed in the hEX S.
According to Mikrotik page (SFP compatibility) such router is not compatible with S+RJ10 module.
So which module would work at 2.5Gb to RJ45 then ?
Does anybody have some experience on this ?
Thanks and regards
It’s mostly not worth your time.
The reason it’s not compatible with Mikrotik modules is that those always connect at 10Gbps on their sfp interfaces even if the negotiated copper speed is 2.5GbE. There are modules that speak 2.5 on their sfp available from other manufacturers. Some people had luck with aliexpress ones.
Thanks for this. Actually I was looking also for other manufacturers on different platforms, but for example I had in the past good experience with 10GTEK, but they refer to be compatible with S+RJ10, so this makes me thinking they could have same issue as the Mikrotik part.
Not really sure which model to try on this router. I can see other 10Gb modules which are fiber based they are indicated compatible, but that won’t be my use case anyway.
I have checked on a CCR1016 which has couple of fibers from ISP (these are SFP-RJ45 as well), one of them is by MikroTik S-RJ01, but the other is indicated as:
CISCOSOLIDOPTICS, part number SFP-GE-T-SO.
At the moment they work at 1Gbitt due to CCR not having different port, but I can check whether this might be indicated as SFP+ and can reach 2.5Gb.
They sell them as 2.5GbE modules. E.g. fs.com has a few.
The hex s is capable of more than 1Gbps, but will probably not be able to use the full 2.5GbE. The first device capable of routing 2.5GbE in fasttrack is the hAp ax3, which conveniently has such a port.
The main reason the hex s supports 2.5GbE is because the SoC manufacturer’s suggested external mac family only has a 2.5GbE capable sfp option.
Thanks for the heads up.
I found this one that from the desc and data could be the one.
About the router, well this was installed in place were the person wanted a really “entry level one”, otherwise a RB5009 or so could have been a better choice, but they wanted to stay on a certain budget, so…. now you get what you pay for.
That’s absolutely fair. But then they get a basic router. It just doesn’t compute for me to then spend money on a 2.5GbE copper sfp. Why not just accept 1GbE and move on?
That’s exactly what we are discussing now with this person.
The topic came about as now they are served by FTTH and ISP are offering more and more 2.5Gb, so he could get that.
However when you budget all and consider what is the real benefit, if you are not having so many users simultaneously generating traffic (like an office), then you won’t saturate as much of that.
So yes 1Gb is more than enough considering what they have now.
Well, this is interesting that I recently bought the MikroTik hEX S (2025) E60iUGS and it’s great little router. One of the reasons I wanted this is the 2.5 gig SFP port. Since I’ve have a few S+RJ10 modules on hand a and all of my switches at home are MikroTik I’ve decided to give it a try. Sure enough it doesn’t work. I even went into the interface settings on both sides to run it as 2.5G BaseT and both sides would not light up. Both ends are using the S+RJ10 module.
I didn’t do my research on the compatibility as I’ve figured long as it’s MikroTik brand it should work? Nope. Not a huge deal but wish I known about it beforehand.
These non 1G and 10G ports always been picky. 2.5G and 5G sounds great on paper but it doesn’t always work everywhere.
To be honest I wish MikroTik simply made port 1 and 2 as 2.5 gig copper while rest of the ports can run at 1 gig. I know the CPU and switch chips can’t achieve full 2.5 gig but still better than 1 gig.
If I am gonna use fiber I rather have it run at full 10 gig speed via SFP+. So 2.5 gig copper port is good enough for general use.
Make note that S+RJ10 module is SFP+ and hEX S (2025) is using "old" SFP (without+) in name. Both SFP revisions are slightly different (power consumption etc), and that is reason why SFP+ module will probably not work into SFP module and its not a good idea to use SFP and SFP+ modules between. Mix and match SFP with SFP and SFP+ and SFP+ modules.
Adding: S+RJ10 is known to be "highly restricted" as far as configuration is concerned.
It will always auto-negotiate with the other side, nothing can be done to set speed via config through the device it has been inserted in.
Not exactly true: SFP+ specs require the "host interface" to tun at 10Gbps ... while 2.5Gbps SFP ports don't hence they can't be called SFP+. And then there's the compatibility mayhem: some devices support different speeds of "host interface" (e.g. by manually setting speed) and some don't. Ditto for SFP+ modules, some are "single speed", some can adapt to what host does. And then there's the "media interface" speed (the "far" side of SFP/SFP+ module, e.g. FO or RJ45) which can be anything (up to host interface speed).
So it's not about power consumption (regarding that, SFP, SFP+ and SFP28 are compatible).
Example: S+RJ10 works (AFAIK) at 10Gbps host interface speed and doesn't work in 2.5Gbps SFP ports. But it can negotiate speed on the ethernet/UTP side (any standard speed between 10Mbps and 10Gbps, including 2.5Gbps and 5Gbps.
Example2: different (passive) DAC cables and FO SFP+ modules work fine also in non-SFP+ ports but may require manual speed setting (on both ends of the link).
Thank you for the insights. I went ahead and ordered the 10GTek 2.5G SFP-T, 2.5GBase-T, SFP to RJ45 SFP as it’s known to work with it.
Why not a RB5009 with the native 2.5G eth port on it?
Cost and size. The Hex wins in this department.
Remember the S+RJ10 would not have been an option anyway, as it is only supported in devices with active cooling (i.e. with a FAN).
Those modules run too hot when in a device without FAN. Ok of course it also depends on the environment, it may work in a server room but in an environment where the room temperature may get up to 30-35C they will have a hard time.
Agreed with you, I have a HEX-S 2025 at my home and it works ok.
But the 5009 is a winwin just in raw power 
and has the native 2.5GbE port.
however my opinion is that