- I just received a new Dongle Max, setting zigbee up for the first time ever
- I’m able to connect to the HTTP UI using IP and updated to the latest firmware + set it into zigbee coordinator mode
- On the
Z2M&ZHA page, it says to connect to port: tcp://Dongle-M.local:6638
- I added those values into zigbee2mqtt, but I don’t see anything in my HA
- I’m sure my HA does not have ZHA
- My Z2M logs says
zigbee2mqtt | [2026-03-01 20:22:19] debug: zh:ember:uart:ash: Waiting for RSTACK... 4600/5000
zigbee2mqtt | [2026-03-01 20:22:20] debug: zh:ember:uart:ash: Waiting for RSTACK... 4700/5000
zigbee2mqtt | [2026-03-01 20:22:20] debug: zh:ember:uart:ash: Waiting for RSTACK... 4800/5000
zigbee2mqtt | [2026-03-01 20:22:20] debug: zh:ember:uart:ash: Waiting for RSTACK... 4900/5000
zigbee2mqtt | [2026-03-01 20:22:20] error: z2m: Error while starting zigbee-herdsman
zigbee2mqtt | [2026-03-01 20:22:20] error: z2m: Failed to start zigbee-herdsman
zigbee2mqtt | [2026-03-01 20:22:20] error: z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
zigbee2mqtt | [2026-03-01 20:22:20] error: z2m: Exiting...
zigbee2mqtt | [2026-03-01 20:22:20] error: z2m: Error: Failed to start EZSP layer with status=HOST_FATAL_ERROR.
- And I cannot establish a connection to it when I run
telnet x.x.x.x 6638 on my Windows PC
- Prime suspect is the dongle’s port 6638 correct?
When dongle’s mode is changed, it doesn’t seem to reboot internally. I had to go into the menu and reboot the dongle for port 6638 to accept connections. This can be a quick fix in the firmware to improve dongle’s user experience.
When I switch to MultiPAN (Beta), port 6638 is available, but seems there are protocol issues as zigbee2mqtt will connect and get disconnected after ~ 10 seconds, possibly bug in this beta.
Multipan has been actively discouraged by the HA Devs for over 2 years now & official support was deprecated last year.
Sonoff chose to ignore that & started saying that multipan is “stable enough” a couple of months before the deprecation.
I’m not saying it won’t work for you, but be aware that others are still running into issues with it & that if you do, you’ll have to take it up directly with Sonoff support.
Personally, I’d rather spend an extra 20-30 bucks & run matter on a separate coordinator
Hi, thank you very much for using Dongle-M and sorry for the issue.
Would you please confirm a few things first:
- You are running Zigbee2MQTT app/add-on on Home Assistant OS, right?
- What’s the serial configuration of your Zigbee2MQTT app (
HA -> Settings -> Apps -> Zigbee2MQTT -> Configuration), are they:
- port: tcp://Dongle-M.local:6638
- adapter: ember
- baudrate: 115200
Note 1: you could use the IP address instead of Dongle-M.local if you know the IP address of your Dongle-M.
Note 2: I would also suggest setting watchdog to 1,2,3,4,5 in Zigbee2MQTT’s Configuration page.
If the above information is correct, then you should be able to solve the Waiting for RSTACK... 4900/5000 issue by:
- Stop Zigbee2MQTT app;
- Change EFR32MG24 Operation Mode from
Zigbee Coordinator Mode to Thread RCP Mode (Web UI → EFR32MG24 Operation Mode);
- Change EFR32MG24 Operation Mode from
Thread RCP Mode back to Zigbee Coordinator Mode;
- Start Zigbee2MQTT app again.
Please let me know if it works for you.
- No, I’m running zigbee2mqtt and HA as 2 separate docker images but I don’t see why it matters
- I’m using direct IP address and the dongle does not behave correctly until I click its
Reboot Dongle-M
I’m already able to get it to work in coordinator mode, what I’m trying to point out is, the dongle does not seem stable when changing configuration, and it seems like it forgot to reboot itself.
Hi, regarding HA’s drop of the support for Multiprotocol, we have replied many times, here are the main points:
-
Multiprotocol is Silicon Lab’s technology, not HA’s. HA’s now-discontinued Multiprotocol App is based on Silicon Labs’ SDK.
-
Silicon Labs is continuing developing its Multiprotocol technology, also with the feedback and contribution from its buisness partners, like Aqara and SONOFF. Please refer to Simplicity SDK Version 2025.12.1 - Release Notes (Feb 5, 2026) | Summary | Simplicity SDK Release Notes | v2025.12.1 | Silicon Labs for the latest update on Multiprotocol.
-
Many manufacturers have launched Zigbee/Thread products based on Silicon Labs’ Multiprotocol technology. They all think it’s stable and ready for commercial use.
-
HA surely has its freedom and reason to abandon its own Multiprotocol app. I don’t think I should comment on it.
- No, I’m running zigbee2mqtt and HA as 2 separate docker images but I don’t see why it matters
Yes, you are exactly right. But running standalone Zigbee2MQTT docker container often involves more configuration than running Zigbee2MQTT app on Home Asisstant OS. I just thought there could be misconfiguration.
I’m already able to get it to work in coordinator mode, what I’m trying to point out is, the dongle does not seem stable when changing configuration, and it seems like it forgot to reboot itself.
Got it. Great point, thanks.
Thanks, but I have some faith in Michael Hu here.
Frankly, while I can’t imagine living without HA, I do have very opposing opinions about certain aspects of their low level architecture decisions, especially the stability of ESPHome acting as a listening server and the issues that come along with it.
In this case of MultiPAN, it is RF, certainly a low level thing to me. And 2 points stood out, I did not have to mess with any jumpers/hardware etc in order to get the dongle to switch from thread to zigbee and what zigbee2mqtt (not part of HA) needs is just an TCP port.
Next, I understand IKEA’s Dirigera is able to communicate with thread and zigbee concurrently, whether it is MultiPAN or not, I have no idea.
But these broadly tells me it is solvable in the software.
And of course, what Michael just said about MultiPAN coming from Silicon Lab.
And zigbee2mqtt currently can’t communicate properly with the dongle when it is in MultiPAN mode. Let me know if there are new releases, I would be happy to test them.
For now my IKEA Vallhorn is working (via Dongle-M).
1 more thing, is it possible to make baud rate configurable? I like to set it to 921600
When Dongle-M is in MultiPAN mode, you will need to run the Silicon Labs’ Multiprotocol add-on from hassio-ihost-addon/hassio-ihost-silabs-multiprotocol at master · iHost-Open-Source-Project/hassio-ihost-addon · GitHub. The Configuration of the Multiprotocol app is like the following:
- Device: choose Dongle-M if it’s connected through USB, or any device if Dongle-M is used as a Network Device.
- Baudrate:
115200
- Hardware flow control:
false
- Network Device: The IP and port of Dongle-M
And the Zigbee2MQTT’s Configuration should be like following:
- port: the hostname and port provided by Multiprotocol app. You can find the
Hostname on HA -> Settings -> Apps -> Silicon Labs Multiprotocol -> Info page. The port is always 9999.
- adapter: ember
- baudrate: 115200
Note: you should delete all old Zigbee2MQTT configuration and database files (basically all files under /homeassistant/zigbee2mqtt) if you want to migrate from Dongle-M’s Zigbee Coordinator to Multiprotocol app’s Zigbee Coordinator.
1 more thing, is it possible to make baud rate configurable? I like to set it to 921600
Currently no, but we are working on it. Please expect it in 1~2 months.
Stability issues in Zigbee Coordinator mode
- After 10 hours, the dongle disconnects
- At around 16 hours, I still could not connect to port 6638
Reboot Dongle-M fixed the problem
Is there a github repo to file issues for Dongle-M firmware?
Is there a github repo to file issues for Dongle-M firmware?
Could you create a topic at Dongle Series - eWeLink Forum, our technicians will follow up.
By the way, you won’t be able to telnet Dongle-M when Dongle-M is connected to ZHA/Z2M. To save resources, Dongle-M only allows 1 active TCP connection on port 6638.
Yes, but the logs show 11:36 disconnected, then I try to telnet at 15:30, cannot open connection.
Did you set Zigbee2MQTT’s watchdog to 1,2,3,4,5?
No, my zigbee2mqtt UI does not have it as I’m running the docker container myself. Will that help Dongle-M accept connections on port 6638?
debug: zh:ember:uart:ash: Waiting for RSTACK… 4900/5000
If you see error log of Zigbee2MQTT like this, then using watchdog to force Zigbee2MQTT to reconnect won’t work.
From what we know, the only scenario where this kind of issue happens is updating ESP32 SoC firmware without terminating ZHA/Z2M connection first and rebooting afterward.
To solve this issue, we normally suggest:
- Stop Zigbee2MQTT app;
- Change EFR32MG24 Operation Mode from
Zigbee Coordinator Mode to Thread RCP Mode (Web UI → EFR32MG24 Operation Mode);
- Change EFR32MG24 Operation Mode from
Thread RCP Mode back to Zigbee Coordinator Mode;
- Start Zigbee2MQTT app again.
If your Zigbee2MQTT doesn’t throw this kind of error log, then reconnection will most likely succeed, thus the purpose of watchdog.
Here is the Zigbee2MQTT’s manual for watchdog: Watchdog | Zigbee2MQTT.
