Misterious Ethernet problem

RouterOS General
1

Hi… I have a misterious problem…

in my network i use either ubiquity and mikrotik device…

when i connect a mikrotik NetMetal 5 in the same router/switch/toughswitch with an ubiquiti airmax M device (nanostation/powerbridge/ect.)

i have this situation:

if ubiquity device boot before mikrotik device… all is ok…
if mikrotik device boot before ubiquity device… ubiquity device ethernet port get “unplugged” ( I see it entering from wifi connection)
and it remain in this state until i don’t reboot device in right order…

I tried everything… and in log file there isn’t nothing…
I tried to change every parameter regarding ethernet side… nothing!!!

with airmax AC Device everything work fine…

someone have answer???
can someone testing it to exclude that it is only a my problem???

Thanks

2

Anyone???

3

What does the MikroTik log show after this happens? The issue is probably auto negotiation related.

4

all ubnt devices have this problem? or only 1 ubnt device?

5

IMHO it could be problem of STP/RSTP protocol. Switch it off and see what will happen.

6

I tried this… but nothing change… same problem…

7

Every ubiquity device with airmax M… with airmax AC device everything it’s ok…

8

Mikrotik log doesn’t show nothing error… problem regards ubiquity part… mikrotik cause it but it doesn’t know that problem exist…

9

I have a similar problem.
After changing the firmware from 6.39.4 to 6.42.1, the ports on 3 routerboards (2xRB750 and 1xRB3011) were randomly restarted.

RB750 restarted ports 2-5. After the firmware change to 6.42.11, the reboot disappeared, but packet loss increased. The port will be frozen at random. It is necessary to turn off the frozen port and then power on.

“Auto Negation” we tried to take off and helped lose, but accidentally frozen ports continue.

10

Maybe it has to do with gigabit port autosensing for the used data cable pairs.

Gigabit ports normally autosense which pairs of RJ45 are available and how they are used. This is why for example you don’t need cross-over cables with gigabit.

Could it be that the two ports sensing timings, on Tik & Uqiuity, are colliding with each other?

As an anecdote, I had once a faulty cable, and my gigabit port would connect over the cable, but after a long delay and only at 100mbit, as 100mbit only requires 2 pairs, while gig all 4


In other words: have you tried putting a plain/dumb switch in-between?

11

Thank you.

Most of these ports are 100Mbps devices. If I disable auto negation, I set 100Mbps. That’s probably not going to happen. It behaves unconditionally and unpredictably. I’m considering downgrading to 6.39.4. I’m aware of the vulnerability.
Does not anyone please ask you something?

“have you tried putting a plain/dumb switch in-between?”
I will try, thank you

12

Hi… I also thinked my problem could be caused by autonegotiation

But I tried many things like set port speed manually… ecc. I don’t solve anything…

Besides, putting a switch in the middle I have the same problem… but if I power off mikrotik and reboot ubiquity it work fine…

In this case autonegotiation is between switch and ubiquity… how mikrotik can change ubiquity working???


Someone known how device understand if in ethernet port there is a connected cable??? I think that could be some electrical problem (impendance)

13

Cable sensing is something different than negotiation.
Cable sensing: which pairs to use for communication
negotiation: at what speed/ when

hence the suggestion to put switch in between to verify if that resolves the issue?

14

When I downgrade to 6.39.4 everything is OK.
With switch also OK.

Now without switch with RouteOS 6.39.4 and everything is OK.

thanks all