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RB260 speed falls do 100M

Posted: Sun Jun 16, 2019 7:30 pm
by solelunauno
I've a strange situation with a couple of RB260 with Swos 1.17, connected together from ether1 to join two fiber links.
Normally link speed of the two ethernet links is 1000Mbps, but sometimes (each 4-5 days) it falls @ 100Mbps and it locks @ this speed.
So, as there is a fixed 200Mbps traffic over this link, generated by a number of IP CCTV cameras to some NVRs, when the link falls @ 100Mbps, all the network is blocked for saturation.
I've already tried to change the two RB260 and also to change the ethernet port used for their link, but they still fall @ 100Mbps every 4-5 days.
So, what can I do to find a solution for this trouble?

Re: RB260 speed falls do 100M

Posted: Sun Jun 16, 2019 10:15 pm
by krafg
To start, you can try to certificate or test your cables. The quality of the cables is also very important. (Leviton, Panduit, Siemon, Furukawa, Belden, Brand-Rex, etc.)

Cables without serious damage, correctly installation and using of cat. 6 or plus is most recommended).

Certificate the fiber and use good quality media converters are also important.

It would interesting what is your equipment at detail and his respective passive elements.

Regards.

Re: RB260 speed falls do 100M

Posted: Mon Jun 17, 2019 10:45 am
by solelunauno
I'm sorry, but I thought it was simple to understand that the two RB260 Ether1 are connected together with a 50cm patch cable, so where is the cable problem?
I've already changed this patch cable and the result is the same.
If I turn off auto negotiation and fix 1000, the link goes down.

Re: RB260 speed falls do 100M

Posted: Thu Jun 20, 2019 1:48 am
by k6ccc
I'm sorry, but I thought it was simple to understand that the two RB260 Ether1 are connected together with a 50cm patch cable, so where is the cable problem?
It was not simple to understand because you did not tell that in your original post. For all we know, you were trying to run gigabit over a kilometer of barbed wire fence :)

Can we assume that the fiber is connected via SFPs to each RB260?

Re: RB260 speed falls do 100M

Posted: Sat Jun 22, 2019 11:51 am
by solelunauno
Yes, the fiber is connected to each RB260 with SFP, and there is only a 0,5m patch cable between the two ether1 ports.

Re: RB260 speed falls do 100M

Posted: Sat Jun 22, 2019 12:20 pm
by pe1chl
In some cases I have seen ethernet ports falling down to lower speeds on MikroTik equipment when strong RF fields are present.
Indeed like you write initially the speed is OK but suddenly it falls to a lower speed, and when disable/enable of the port or reboot of the unit it is back at higher speed.
Could it be your installation experiences strong local RF fields? (e.g. a transmitter, some RF based heating system, etc)

Re: RB260 speed falls do 100M

Posted: Sat Jun 22, 2019 1:00 pm
by solelunauno
No, the site is a beach hotel, and not a trasmitter tower. And it's vey far from the kitchen. The only think I could find is that there is a fixed and continuous 250Mbps traffic generated from IP cameras to NVRs, passing through those two RB260. So, when ether1 link falls ò 100Mbps, all this network is compromised, because the camera traffic saturates the link between RB260s.

Re: RB260 speed falls do 100M

Posted: Sat Jun 22, 2019 1:34 pm
by pe1chl
I think the traffic is not a factor in this. It is some kind of interference that causes the negotiation to misbehave.
Aside from the obvious causes like a bad cable or bad contact, I wanted to point out that it can be RF (indeed a transmit tower, amateur radio installation, etc)
But apparently that isn't the case there. You could try a slightly longer cable (like 1.5 m), I once experienced problems with a very short cable (15cm) but 0.5 m should normally be fine.