I use all the solution but not working,at the ed I change 24 v POE wiht 12 V and it’s working
Hi
I try all the solutions,just when I change 24 V wiht 12 V POE the ehternet port go alive.
how long is your cable going to the cpe from poe?
Hi,
Just wondering if there has been any progress on this particular quirk, as i am having a similar problem with an RB411, and have so far tried every solution described in this thread except sheilded cable and shielded ends, and have had no luck.
The RB411 in question is being used as the client side for a 5km link, and has a wrt54g running ddwrt hanging off the ethernet port and refuses to autonegotiate with it, only producing a fast blinking light on whatever ethernet port on the wrt its plugged into, only solution i have found so far to maintain a link is manually set it to 10mbps and turn autonegotiate off on the wrt and the mikrotik, however the rx pair still drops every few minutes, one difference however is i can disable and enable the ethernet port in question from my end and this brings the port back to life, until the next drop.
Am considering upgrading the client to a RB532, but if theres a fix available or in the works id be glad to hear it.
Kind regards
Ralphy
Got the same issues. For the first time on RB433 and then on RB333. Always it was in hand with changing the machines on the other side of ethernet cable. After reading this thread I switched the ethernet ports on RB to 10MBps half duplex and now it works again !
There is a necesary thing about it - reboot the RB after this change
So… after few days of testing I must say, that this was not the solution 
Someone has any news about this ?
I have the same problem on device running dual nstreme.
RB433ah as ap is allright. As client, I have two r52 cards, dual nstreme 5ghz, newest routeros, bootloader(also tryed older versions).
I changed the board(for another rb433ah), changed cable(also connectors), changed ports, power supply(is 12V).
Netwatch in log shows that wireless part is ok, it freezes just ethernet. It freezes randomly, usually once a week. After freezes it needs power cykle.
The last thing I tryed now is disabling auto negotiation on both side and see if it happens.
How did you solve this problem? Or does it still persists? It seems that this is just problem with big packets(I have other rb433ah on site, withou nstreme, also more bandwitch going through and they dont freeze).
Mikrotik please react. Do you sleep?
This issue is more than 1 year i believe…
as till now still no solution yet…
The most likely should be the Ethernet chipset issue…
I turned on autonegotiation and no packet loss, and no eth up, down.
But with turned autonegatiation routerboard will reboot once and more time a week(freeze and I must switch it off from electricity).
Time to change for better products UBNT and ROCKET???
What mikrotik, are you able to react?
Is that problem of rb 4xx or also rb800?
what is STP???
Pls help!!!
Because i have the same problem and cannot find the solution
STP=Spanning Tree Protocol
http://wiki.mikrotik.com/wiki/Manual:Interface/Bridge
STP or RSTP is not going to change noting
also hire same
http://forum.mikrotik.com/t/evry-day-interface-wlan-ether-stop-passing-data/56261/1
http://forum.mikrotik.com/t/wireless-interface-stop-transmitting/56314/1
I send and send and send about that problem
no answer from mikrotik.
guess mikrotik is in sleep mode 
I am having similar behaviour…
Harware on both sites → Routerboard 435G + R52hn + Gigabit Poe Injector
The wireless part uses protocol nv2 with nstream enabled
Both routerboards are running Ros 5.18
Both routerboards are connected to Cisco routers on via ether 1
The cables are cat6 sftp grounded on the data-room side.
Firstly, i had the routerboards configured as ap-bridge and station-bridge, but once every 2 days, the one or the other routerboard would loose Ethernet connectivity (transmit ok but no receive)..
Only a reboot would solve the problem.
I then changed the configuration and seted up the good old station-wds mode bridge but the symptom persists…
Is there anything else i can try?
I cant find anything in the logs…
After many years of routerboards, many bad capacitors and now this…
Any suggestions?
try to put between those two routers some basic switch. I did it and it works now. It seems to be problem of rb 4xx connected to each other and when big packets go through(nstreme), I tryed everything else, nothing helped, just this…some switch for 7euro…now I plan to change one of rb for alix board…
I had the same problem on my RB411. It just appeared a few days ago after 3 years of normal (Ethernet at list) operation.
After some research I discovered that the problem was triggered by teamspeak (http://www.teamspeak.com) installed on a pc by my son (I have a P2P connection).
From what I understaind, teamspeak is doing some kind of streaming that produces “unacceptable” to RB frames.
I uninstalled teamspeak and the problem is gone -hope for ever…
Although, I believe Mikrotik should have had some kind of immunity mechanism to prevent interface crash…
(ROS 5.20)
We are recently deploying Radio link on RB411L With R52HN Card after installing the link entire network get hanged how ever on the same location and setup we have deployed Radio link With RB411 With R52H Card since last two years it is working fine , After deploying the new link on RB 411L we are facing that network get hanged and this has happen with all the link where we have deploy RB 411 WITH R52H Card which was working fine also on same antenna new Link does not get estlabish which was previosuly used by old radio ,We have to do lot of alignnment .Can any one suggest what could be the problem as all possiblity on RB 411L Card has been taken care like disabling auto negotation setting the link on half duplex but still after 2 to 3 hrs we have to reboot the radios .