Hi all,
I use two S+ RJ10 (in two CRS310-8G+2S+IN) to perform a stable 5G link over my Cat5e Cables. But as I plug them in, thy perform auto-negotiation with 10G but it fails every second and reconnects. I tried to disable auto-negotiation, but that didn’t work (mybe because of spec). Then I tried to set advertising speeds only up to 5G full. But auto-negotiation also links with 10G unstable. Is there a way to limit to 5G or any other rate?
Thanks a lot!
Cat5e is only specified up to 1Gbps.
Use proper cabling (cat6a or cat7).
Thank xou for your reply.
You’re right and I know that cat5e is not optimal for this data rate. But in my scenario there is only cat5e. Mikrotik rates this SFP+ for 5Gig over cat5e (https://i.mt.lv/cdn/product_files/sfp_splusrj10_190212.pdf). And the other thing is, that even if i want to go down to 1 Gig, i don’t know how. That was the main part of my question. I want to change the negotiated rate, so that i can decide, how fast the link should be. Thanks!
I don’t have RJ10 in my device but do have RJ01 (same manufacturer).
Assuming it works the same:
I would think disable the unwanted speeds (fold the fields up), leave auto negotiation on.
Set the same on both sides.
But that’s exactly what mGig is supposed to be for. Running 2.5 & 5Gbps over Cat5e. If you had Cat6a or Cat7 you could run 10Gbps.
But the fun is, that doesn’t always work either. I have used a known good 20m Cat6a cable and it would not go higher than 5Gbps. All in all, speeds higher than 1G over copper suck. And don’t get me started on the power usage and heat of 10GBASE-T SFP+ modules. 10GBASE-SR & OM3 multimode fiber FTW. The cabling costs the same, and the optics are a third the price and keep to a sane temperature. Use 10GBASE-SR if at all possible.
But I’m aware that it’s not always possible, and sometimes you have to make do with what you have.
Thanks.
if I understood you correctly, i’ve tried this already, but the link is negotiated with 10G, no matter what i do in settings. I have screenshots in the attachments.
Both sides the same settings ?
Already tried disabling/enabling the ports after that change ?
Yes i tried this; i also rebootet both devices…
I am confused, that i have 5GFull in my settings, and under “Status” there is advertised from 10m to 10 G.
Just re-read the Help pages …
https://help.mikrotik.com/docs/display/ROS/Ethernet
What if you set autonegotation off on both sides and set speed on 5G ? Or 2.5G ?
If that doesn’t help, maybe ask support how it is supposed to be done.
It should be possible (otherwise they could not have tested it themselves).
This might be what you are missing.
/interface/ethernet/set <INTERFACE> speed=5G-baseT auto-negotiation=no
or
/interface/ethernet/set <INTERFACE> speed=2.5G-baseT auto-negotiation=no
speed: Sets interface data transmission speed which takes effect only when auto-negotiation is disabled.
On an unrelated note — [STH] SFP+ to 10Gbase-T Adapter Module Buyers Guide
https://www.servethehome.com/mikrotik-srj10-review-convert-sfp-to-10gbase-t-inexpensively/
https://www.servethehome.com/sfp-to-10gbase-t-adapter-module-buyers-guide/
From another forum post about the same topic,
http://forum.mikrotik.com/t/does-the-css610-8g-2s-sfp-port-with-s-rj10-support-2-5gbe-speed/163642/5
I already tried without auto-negotiation and set speed to 1G/2.5G and 5G but the switch does always 10G link. I absolutly have no idea why. I tried with two CRS310-8G+2S+IN and also with 1 CRS and one RB5009UG+S+IN.
I got an answer from the support:
The S+RJ10 does not support forced link speeds and does not support speed advertisement configuration, it will always negotiate to the highest possible rate.
Unfortunately, it is not possible to change it
Then how were they able to test other link speeds ???
If I connect the module with a f.e. 2.5G Port, then auto negotiation does 2.5G. But it is not possible to force the module to run at 2.5G if the other site is capable of 10G.
That PDF you linked in post #3 specifically mentions testing from S+RJ10 to S+RJ10, indicating maximum allowed cable lengths for various speeds.
So I don’t understand how they managed to do that if speeds can not be controlled.
You’re right. This makes no sense…
The other way around: take cable of certain length and see what a pair of S+RJ10 can negotiate. Make cable slightly shorter and repeat.
The thing being: if you can not set rates which are advertised, it doesn’t mean that link peers don’t check feasibility of certain link speeds over a particular physical link (i.e. measure SINR and if it doesn’t meet required level, go with slower speed). Setting advertised values doesn’t mean that peers will select the highest common value automatically, they still measure the link quality. For example: anything faster than 100Mbps requires 4 pairs. So if both link peers support 1Gbps, but cable only provides 2 pairs, then link peers will try with 1Gbps, will measure link and notice failure on two pairs and will fall back to 100Mbps. Even though both advertise support for 1Gbps.
The only unknown remaining is the meaning of “other brand” … did they actually test (and which module(s)?) or did they copy-paste specifications from standard?
I have the same error with passive mikrotik DAC cable. 10gbit is unstable with my rb5009. Random link down and link up. 5gbit is stable. I disabled auto negotation. Same error on 10gbit. 7.13RC3.
That’s so frustrating. My physical link (Cat 5e, yes I know it can only go to 5Gbps) is very unstable with 10G connection. It will handshake over 10G but fail immediately.
I wish I can force the link to handshake over 5GE but it won’t work. The module won’t follow the advertise speed at all.
My understanding is, the speed on that page means the link speed between router and the module, but not the module to the other device. Because if I disable the 10G base CR option on the interface, it will stop working at all.