log: excessive or late collision, link duplex mismatch ????

RouterOS Beginner Basics
1

in log keep this come up:
memory interface, warning excessive or late collision, link duplex mismatch
???!!!

what’s this?



err.png

2

what board you have?
What do you have connected to ether3 interface and what ethernet settings you have on that device?
How long is the ethernet cable?
At what linkspeed the ethernet is linked under status?

3

I have this same problem after install 6.10 version

I have a bridge in six EoIP and one ethernet and in this ethernet say this message warings.
Cable length for this ethernet is max 0,5meters (patchcross) for next router.

RH1000x2.
previous version 6.7 worked well.

4

I have the same problem on multiple 751G-2HnD’s that are connected to 750UP’s via 60-70m cables.
The problems started after upgrading to 6.10.

Why am I always afraid to upgrade to latest version lately?
Last year due to port flapping we had to substitute CCR1036-12G-4S in a large hotel resort with RB1100AH because the latter worked, it struggled but it worked.
I hope that this will not be the same scenario where the router works for couple of hours and decides to go on a holiday.

5

In my experience (mostly with Cisco devices) late collissions are the result of bad cables.

6

Hi friends, i have the same error in this v6.10 “ether2 excessive or late collision, link duplex mismatch?” my setup is extremely simple:

RB450G - ROS v6.10

ether1-2-3-4 → RSTP Bridge
ether5 → WAN

In the bridge only use de ether1 linked to a RB750UP at 30mts

But… the error is logged at ether2 (unused)…

Any news about that?

EDIT: I`ll test updating the 750UP to v6.10… (actually v6.9 w/firm 3.12)

Thanks!!!

7

Hi Guys

We are having the same problem here are our details.

RB2011UiAS with LCD
Router OS 6.11
Routerboard Firmware 3.12

8

Enjoying this problem on RB1100AHx2.

9

Same problem here after upgrade from 6.1 to v6.11 on RB750G . Other side is RB411AH v5.22 with default ethernet config .

10

Same problem. RouterOS 6.11, Routerboard RB2011iL.

11

Hello,

The logs are warning about a misconfiguration. There is a duplex mismatch on the
link. RB411AH has disabled autonegotiation (100Mbit, full duplex), but the RB750G
has autonegotiation enabled which leads to packet collisions on the link.

More information: > http://en.wikipedia.org/wiki/Autonegotiation#Duplex_mismatch

These log messages were not implemented in RouterOS version 5.

Regards,
Janis Becs

My problem solved .

12

omidkosari
I am experiencing the same with RB1100ahx2 / ROS 6.11/6.12 , How you managed to solve it ?
[There was no problem with 5.26]

13

You should always configure both ends of the connection the same way.
So if you configure one end to autonegotiation you need to configure the other end also for autonegotiation.
If you configure one end to 100/full, the other end must also be 100/full.

Configuring one end to autonegotiation and the other end to 100/full WILL cause errors.

14

Glad to see this feature is in 6.x…even setting gigabit ethernet to be hard coded on one side and autneg on the other can cause issues. Autoneg is the way to go unless you encounter a problem and then hard code both sides and move on.

15

I faced this issue in 6.11/6.12/6.13 on rb1100ahx2 few days back at wisp operator.
I tried EVERY POSSIBLE method available in the mikrotik forum and at Google, but no use.
Although this error was not effecting any communication but the wisp operator was getting annoyed by seeing these errors and relating every issue of network with this one :confused: So I reverted back to 5.26 and the error is not appearing in LOG window and the operator is happy now :laughing:

16

You could disable default logging entry about warnings and add custom entry which logs all except interface warnings.

/system logging
set 2 disabled=yes
add topics=warning,!interface
17

Anybody here, got answer this problem ?

ether5 excessive or late collision, link duplex mismatch?

18

Bom dia, Pessoal.

Eu conseguir resolver o meu problema dessa mensagem, após conferir os modos duplex e certificar que estavam todos alinhados com a mesma configuração em ambas as pontas. Eu atualizei a minha RB2011UiAs para a versão mais nova 6.18 e as mensagens pararam de ser emitidas.

Atualizem suas RB´s que estão com esse warning depois de conferir os modos duplex que possívelmente também será resolvido.

Abraços

19

I’m receiving the same warning on a RB751U-2HnD with Router OS 6.19, but in my case it’s a computer connected. Is the wire that connect the computer the cause?

20

I solved this issue opening a ticket with my ISP.

In my case, the problem was the ISP Routers’s port, which was not in Auto mode. And no, the ISP didn’t tell me wich was the value configured before.