eWon Flexy over 3G MQTT connection fail

pgreiner · August 2, 2018, 1:03pm

Hi,

I fail to establish an MQTT connection using the simplest of programs (like the sample https://ewonsupport.biz/mqtt/program.bas.txt).

When running the program, I always get the message "Operation Failed (28) : MQTT “CONNECT”. My eWon is correctly connected to the Internet, and I really struggle to find a solution for this… I would be really grateful for any help, and can provide any additional detail as needed. The internet connection is obtained via the FLB 3202 3G extension card.

I think the problem might be related to port 1883 not being open, but I did not find a way to open it from the eWon web interface. Firmware version is 13.0s0.

Thanks in advance for your help,

Philippe

jseanor · August 2, 2018, 1:04pm

@pgreiner

Are you trying to use the eWON test server found at: https://ewonsupport.biz/mqtt

The eWON doesn’t need any internal ports on the device opened.

pgreiner · August 2, 2018, 1:25pm

Yes, I use the test program as-is, without changing the test server adress… Is it possible that the port is blocked by the SIM card network operator ?

jseanor · August 2, 2018, 1:27pm

@pgreiner

Can you give the code found at this link a test:

https://forum.hms-networks.com/t/mqtt/2623/2

pgreiner · August 2, 2018, 1:35pm

I’m not allowed to download the file (the link on ‘THIS’) apparently…

jseanor · August 2, 2018, 1:56pm

@pgreiner

Give it a go now. There was an issue with the file, sorry about that.

pgreiner · August 2, 2018, 2:03pm

I still get the exact same error when line 15 (MQTT “Connect”) is executed…

jseanor · August 2, 2018, 2:03pm

@pgreiner

Can you provide a login to the unit so I can take a look?

pgreiner · August 2, 2018, 2:22pm

How can I configure this remote access ?

jseanor · August 2, 2018, 2:23pm

@pgreiner

You just need to follow the setup documents. Here is a video that should help:

https://ewon.biz/e-learning/library/cosy-131/configure-ewon-for-remote-access

pgreiner · August 3, 2018, 1:09pm

I configured the remote access.

jseanor · August 3, 2018, 1:10pm

@pgreiner

The provided credentials did not work, can you confirm that they are accurate?

pgreiner · August 3, 2018, 2:05pm

removed

jseanor · August 3, 2018, 2:07pm

@pgreiner

I have resolved the issue. Your cellular provider was not properly resolving the DNS address of the MQTT server. In order to resolve this I manually forced Google DNS into your eWON and then tested again and it worked properly.

Alternately you may also use the IP address of the server to establish the MQTT connection. In this case however I simply set the DNS servers.

Give it a test when you can.

pgreiner · August 3, 2018, 2:16pm

Great ! Thanks a lot !! How did you manually force Google DNS into the eWON ? I would love to know, as I will have to follow the same procedure on other eWONs. Thanks again !

jseanor · August 3, 2018, 2:31pm

@pgreiner

Sure! Take a look at the steps below.

Forcing Google DNS:

Open the eWON webpage
Select Setup from the left
Select System Storage Tabular Edition Edit Com cfg
In the filter search bar enter DNS
Double click EthDNS1 and set 8.8.8.8
Double click EthDNS2 and set 8.8.4.4
Click save