Be3 media ports flapping and severe WinBox lag with minimal load

[dika324]

After waiting several months, I finally received the be3 media a few days ago and configured it right away. Even with a very basic setup and almost no load, the router gets quite hot. After only 1–2 hours, it goes into a really bad state: all ports start flapping up and down.

The connected devices are still online and working — it’s the router’s own ports that keep dropping.

I reset the configuration again and left it with nothing extra, only internet and a basic bridge. After running for a while, the ports started dropping again.

CPU and memory usage are basically idle, so I have no explanation.

On top of that, WinBox becomes extremely laggy. Typing in the terminal takes seconds for each character to appear. It’s terrible.

Has anyone else experienced something like this?

I own several MikroTik devices and have installed dozens of them at different locations, but I’ve never had this kind of issue. I switched back to my ax3 with exactly the same setup, and everything works perfectly.

[erlinden]

What exact RouterOS and firmware version is running on this device?
Anything particular about the surroundings, like in a closet with little air flow?

[Kindis]

Concerning I must say. Can you correlate CPU temp to issues with port or winbox speed?

Does a restart fix the issue or must the device cool down for it to work again?

67C is also not that bad especially if this is in Europe during heatwave. Hopping this is a software issue and not hardware!

[dika324]

This is my diagram (generated by GPT).

Yes, I’m in Europe, but the router is at home in a well-air-conditioned room, around 24°C.

Maybe the bridge between ether1 and ether2 is causing the problem, but I’ve been using the same setup on my ax3 for years without any issues.

[xRadio]

The same issue with the ports disconnecting. I changed the Ethernet cable and tried different ports. However, port 3 keeps disconnecting constantly.

                                       **Update!!!**

1. Early issues with 2.5G technology

When the industry began its widespread transition from 1 Gbps to 2.5 Gbps, the Realtek RTL8125 became the most affordable solution. As a result, it was integrated into nearly every mid-range and gaming motherboard from manufacturers such as ASUS, Gigabyte, and MSI. However, the 2.5GBASE-T standard itself is much more sensitive to electrical interference, cable quality, and auto-negotiation than the mature 1 Gbps standard.

2. Compatibility issues with switches (especially MikroTik)

This controller is known to behave inconsistently with certain switch chipsets. My combination is a classic example:

• PC: Realtek RTL8125
• Router (hAP be3): Qualcomm QCA8386

When both devices attempt to operate at the maximum 2.5 Gbps link speed, their auto-negotiation algorithms may fail to synchronize correctly. The Realtek controller may briefly change its signaling characteristics, causing the MikroTik switch to interpret this as if the Ethernet cable had been unplugged (link down). The router immediately drops the connection and then brings it back up (link up). For the user, this appears as a brief network interruption lasting 1–3 seconds, which is enough to disconnect online games or interrupt downloads.

3. Poor power management implementation (Energy Saving)

Realtek heavily promotes technologies such as Green Ethernet and Energy Efficient Ethernet (EEE). In practice, however, these features are often implemented too aggressively in the Windows drivers. As soon as network activity decreases—for example, when you're simply reading a webpage—the network adapter attempts to enter a low-power state or reduce power consumption. The MikroTik hAP be3 immediately detects the change in the electrical characteristics of the link and drops the connection.

Be sure to disable the following settings on your network adapter:

Green Ethernet Disable
Energy Efficient Ethernet Disable

The port disconnects are still happening. The network card cannot operate reliably at 2.5Gbps → switching the port speed to 1Gbps.

Any other device running at 1Gbps or lower works without any problems on any port. I don’t have any other 2.5Gbps network cards to test with, except for this problematic Realtek 2.5GbE adapter.

I’m monitoring it! I’ll report back later.

[dika324]

Thanks @xRadio

my port 3 is a server, where all green and energy things are off for sure. This same setup is working super from years on ax3
Any idea what I can do or maybe to return the product is the best I still have time from my 14 days

[BartoszP]

@xRadio

1. Early issues with 2.5G technology

When the industry began its widespread transition from 1 Gbps to 2.5 Gbps, the Realtek RTL8125 became the most affordable solution. As a result, it was integrated into nearly every mid-range and gaming motherboard from manufacturers such as ASUS, Gigabyte, and MSI. However, the 2.5GBASE-T standard itself is much more sensitive to electrical interference, cable quality, and auto-negotiation than the mature 1 Gbps standard.

It's a AI generated text.
We can substitute Realtek with other brand and the text would be also valid as all brands promote these ECO solutions.

There is a proper topic on EEE on the forum: EEE on Mikrotik - #9 by jbl42

[xRadio]

In this case, I consulted AI because I never had this issue with my previous router (Keenetic). The Realtek 2.5GbE network adapter worked reliably at 1 Gbps on that router. Unfortunately, I don't have any other 2.5Gbps network adapters to compare with.

You may want to try forcing your network adapter to 1Gbps. If you're experiencing the same issue, you might find that the port becomes much more stable and stops disconnecting.

                             **UPDATE!!!**

I switched the network card from 2.5Gbps to 1Gbps, and the port disconnects stopped. However, MikroTik positions this device as having ports that support 2.5Gbps speeds.

[macgaiver]

it can be cable issue also ( cable/connectors/bends etc)

[xRadio]

To sum it up, I connected the WAN cable to port 2 instead of port 1, and all the port disconnects stopped. I don't really like having the WAN connected to anything other than port 1, but as a test, this worked exactly as MikroTik Support suggested. I also sent them a supout.rif file for further analysis.

I've only observed the port disconnect issue with the Realtek 2.5GbE network adapter. All of my other devices—switches, access points, the TV, and the Raspberry Pi 4B—that are physically connected to the MikroTik ports maintain a stable connection and do not experience any link drops.

[xRadio]

Don't rush to return the router! I believe the port issues will be fixed in upcoming updates. I've decided to keep this incredibly powerful MikroTik hAP be³!

At least I contacted MikroTik Support and sent them my supout.rif file for analysis. They replied that the issue has been identified and will be fixed in a future update.

I had an issue where all ports except the first PoE port were randomly disconnecting. Ports 2, 3, and 4 have EEE (Energy Efficient Ethernet) enabled—you probably know what that is. In any case, MikroTik Support has acknowledged the issue and said it will be fixed, so don't rush to return the router!

[wdl]

It also makes sense, given that the 2-5 ports are controlled by a separate switch according to the block diagram. It’s highly likely to be an offloaded option implemented at the silicon level, and wasn’t enabled on the main SOC (one controlling port 1).

[Etem]

I think I'm facing a similar issuew with my hap be3. The router was working perfectly fine for a few days, until the ports started flapping:

2026-07-25 18:04:35 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:04:37 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:04:37 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:05:02 interface,info ether2 link down
2026-07-25 18:05:02 interface,info ether3 link down
2026-07-25 18:05:02 interface,info ether4 link down
2026-07-25 18:05:04 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:05:06 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:05:06 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:05:32 interface,info ether2 link down
2026-07-25 18:05:32 interface,info ether3 link down
2026-07-25 18:05:32 interface,info ether4 link down
2026-07-25 18:05:34 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:05:36 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:05:36 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:06:03 interface,info ether2 link down
2026-07-25 18:06:03 interface,info ether3 link down
2026-07-25 18:06:03 interface,info ether4 link down
2026-07-25 18:06:05 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:06:07 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:06:07 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:06:38 interface,info ether2 link down
2026-07-25 18:06:38 interface,info ether3 link down
2026-07-25 18:06:38 interface,info ether4 link down
2026-07-25 18:06:40 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:06:42 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:06:42 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:07:08 interface,info ether2 link down
2026-07-25 18:07:08 interface,info ether3 link down
2026-07-25 18:07:08 interface,info ether4 link down
2026-07-25 18:07:10 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:07:12 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:07:12 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:07:44 interface,info ether2 link down
2026-07-25 18:07:44 interface,info ether3 link down
2026-07-25 18:07:44 interface,info ether4 link down
2026-07-25 18:07:46 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:07:48 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:07:48 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:08:19 interface,info ether2 link down
2026-07-25 18:08:19 interface,info ether3 link down
2026-07-25 18:08:19 interface,info ether4 link down
2026-07-25 18:08:21 interface,info ether2 link up (speed 100M, full duplex)
2026-07-25 18:08:23 interface,info ether3 link up (speed 1G, full duplex)
2026-07-25 18:08:23 interface,info ether4 link up (speed 1G, full duplex)
2026-07-25 18:08:45 interface,info ether2 link down
2026-07-25 18:08:45 interface,info ether3 link down
2026-07-25 18:08:45 interface,info ether4 link down
2026-07-25 18:08:47 interface,info ether2 link up (speed 100M, full duplex)

I don't have any 2.5 Gbps capable devices, so no idea why this is happening. Reloading the router seem to fixed the problem and it has been stable for an hour now.

I have opened a ticket to Mikrotik and waiting for their feedback.

[xRadio]

I'd be interested to see what response you get from MikroTik Support in your case.

On my setup, everything is completely stable when the link speed is forced to 1Gbps. However, when I switch back to 2.5Gbps, the port starts disconnecting again.

[dika324]

@Etem Keep us posted. Thanks - totally the same issue

@xRadio how to force the ports to 1Gbps?

[infabo]

@xRadio

Ports 2, 3, and 4 have EEE (Energy Efficient Ethernet) enabled—you probably know what that is

Ah, EEE which is - according to manual - disabled on all Mikrotik products.

"IEEE 802.3az Energy Efficient Ethernet (EEE) capabilities are disabled on all our products. There is no option to manually enable or disable EEE settings."
Ethernet | RouterOS Manual.

[xRadio]

On the router?

For example, port ether2

Terminal Command:

/interface ethernet set ether2 auto-negotiation=yes

/interface ethernet set ether2 advertise=1000M-full

But I did this on the PC’s network adapter, not on the router. However, it can also be done on the router because the devices automatically negotiate the link speed with each other. I can see that these kinds of problems are not limited to just us.

[xRadio]

That's strange. I was told that EEE is disabled only on ether1, and they asked me to move the "problematic" network card to the first port for testing. However, I think the issue is more likely related to the physical layer and the way the hardware negotiates the link between the devices.