InfluxDB docker blocks KNX connection of OpenHAB 3.1 docker?

  • Platform information:
    • Hardware: Synology DS716+ / Intel Celeron N3150
    • OS: DSM 6.2.4-25556 / Docker 20.10.3-0554
    • Java Runtime Environment: bundled with docker
    • openHAB version: docker “openhab/openhab:latest” (3.1)
  • Issue of the topic:

When starting the InfluxDB docker before OpenHAB, the KNX connection fails with following error in the log:

[ERROR] [NXnet/IP Tunneling {redactedIP}:3671] - establishing connection failed, timeout connecting to control endpoint /{redactedIP}:3671

When OpenHAB is started first, everything is working fine.
All other bindings (MQTT, Sonos, Gardena, Hue) are working as expected in both cases.

  • knx.things
Bridge knx:ip:IPIF "MDT IP Interface" @ "Verteilung" [
  • OpenHAB docker running with network “host”
  • InfluxDB docker running with one simple forwarded port 8086->8086

I guess this is probably more a Docker/Synology/… issue, but all my research was unfortunately unsuccessful. Perhaps someone here has come across the same problem.

Thanks in advance!

I would suggest to start the influxdb docker image - not starting the KNX part yet and then run:

netstat -tulpn | grep influx

this should show the ports that are in use by influxdb.
Suspect is that you find UDP port 3671 being listed there.

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Thank you @Wolfgang_S for your suggestion. I had to modify the command as the influx process is hidden behind docker-proxy. I did this from the host system.

As you can see the only port the influx docker listens to is 8086.

sudo netstat -tulpn | grep docker
tcp        0      0  *               LISTEN      3119/docker-proxy   

sudo netstat -tulpn | grep 3671 

Anyway - thank you: I have learned something for sure! :slightly_smiling_face:

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Hello Tobias,
is the MDT interface a router or a simple gateway?
A KNX/IP gateway allows only one connection.
I am using knxd in a docker environment to enhance my Hager KNX IP Gateway with routing function.
Apart from that I have a similar setup as you: MariaDB server and openhab run in a docker container.
The reason why I mention this: Could it be that something else is accessing the MDT Interface which you don’t expect?
I had such phenomena when running the Group monitor in ETS and knxd solved this.

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Thank you @marco_hoefle for the idea. The MDT IP interface is in fact a simple gateway. But the influxdb does not interact with it at all.

But I’ll see if using an external knxd instance could be a workaround for the issue.

I hope I can find some time to test this out - such experiments do not fit very well into the typical “after work, after kids/family, one hour spare time before bed”-evenings.

I know, that’s why I get up early on Sunday mornings :wink:
I attached my Docker Build and Run files, just rename the file to knxd.tar.gz
in knx.ini use the IP address of your gateway,

knxd.tar.gz.pdf (2.0 KB)

With knxd you make from a Gateway:

a Router:

Let me know if it works.

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