Have you guys experienced any hardware issues with RB951G-2HnD?
I'm quite puzzled here... I've been using this model for an year now. At my home I have two RB951Gs running, without any obvious issues so far. So recently I bought another one for my brother's apartment and since than, the problems started...
1. As the RB is constantly monitored by Cacty, we realized that sporadically the board was just "locked" doesn't answering to any requests. After a couple of minutes, the devices restores it's functionality. I sent the board to the distributor, and they've replaced it.
2. Now the replaced device.... Again, as there's constant monitoring (my brother even has rented a server that monitors the connection to it's public IP address and sends an SMS if there isn't a response) we realized that again sporadically there is a connection drop. This time the device isn't locked, it responds to all requests from the LAN but the outbound interface is not able to sent traffic! The link is up, but the router is not able to resolve the MAC address of the ISP's gateway address. In about 5 minutes, the problem is gone. It happens relatively 2-3 times for every 24 hours.
3. I changed the outbound port from ether1 to ether5 - the same result.
3. So on Saturday I tried another router. I've had a spare RB951 so I thought to myself - let's give it a try. I exported the config and uploaded it to the spare RB. It worked for... approx 18 hours, than not only I've had the issue with the outbound interface but also the device became completely unreachable. At some point part of the configuration was lost... I realized that the bridge-local bridge interface was somehow gone?! So I've again replaced it and made an arrangement with the local distributor to replace it. I'll see tomorrow if they'll honer my request.

So my question is... Is it possible to have so many hardware issues? For me RB951G has always been rock solid platform for the past 8 months maybe, but know... I'm not quite sure.
And just to mention that the ISP's line is fine. It was checked numerous times, including last Friday. When my brother's server is directly connected to the ISP - there are hardly any drops for many months, only when there's a confirmed issue with the provider's network.
Have you experienced similar hardware issues with your RB951?

I think I was able to pinpoint the reason... Lots of traffic! When I initiate a constant traffic of around 40Mbps over the router - the outbound interface fails after few minutes, it cannot sustain it. The interesting part is though that the router does not fail by itself - its reachable and I can see what is happening.
The problem is that the outbound interface stops sending traffic. I checked the arp table when the issue happens - it does not show any entry for the ISP Gateway, which is the reason why the router does not send any traffic. But... even if I put a static ARP entry, the routers still fails to send traffic over the outbound interface. The interface itself is shown as up and running, but strangely enough, no traffic passes over that interface. After some time, it recovers.
How to solve this? This is the fourth router I put in there? The same result... Am I reaching some sort of hardware limitation?

Am I the only one facing this issue with RB951G?

What RouterOS version are you using? Please upgrade to the latest version and also upgrade the BIOS to the latest version.
Please make a support output file when the problem is happening and send it to support@mikrotik.com

I'm running the latest image 6.12.
All right, next time it happens, I'll send the support file.

also could you tell us to what device the board is connected as maybe there is some compatibility problem with ethernet connection?

also could you tell us to what device the board is connected as maybe there is some compatibility problem with ethernet connection?

As far as I know from the provider, the device on the other end is a simple non-managed TP-link switch... This is the switch that aggregates the Ethernet connections within the block.