I have developed a Modbus Server and is listening on port 502. I have added the INPUT rule for the tcp protocol, port etc. I have also added sometimes an output rule Then I have put all in ACCEPT policies. INPUT, FORWARD and OUTPUT…like “iptables -P INPUT ACCEPT” and so on. But it still does not …

Ye it has. and is comunicating with our servers. I HAve also checked it with “cm data”

it is communicating with your server → this is TCP client only. But you are now holding a TCP server on port 502 on module, so there is chance that the network blocks this port 502, or the IP address is not exposing to public. BTW, have you tried other port like 80 or 21? Can your PC ping the mo…

Our app has several ways of communication. It connects with our severs, but we also can configure a Modbus TCP Server They do not respond to ping when I PC ping to the public static IP They only respond ping via USB, when I ping 192.168.2.2

then it seems your network does not allow to do so

I do not think network is blocking 502 port, becase I checked the same with a SierraWireless OpenAT Q26 and is working fine

is it only working on 2G network? You can capture wireshark log and see if there is any clue. [image] View pings sent from an external device to mangoh red Legato Application Framework @jyijyi Is there a step by step process you can provide?

Thanks!! for your Quick responses…I’m going to try with 2G, trying to use wireshark and read that post

BTW, when you work with 2G network with Q26, is that your PC can ping the module with public IP address? I think the first step is to let outside PC to ping the module with public IP address

Yes in that case my PC can ping Q26 with public IP adress. Yes!! I am going to try to ping WP85 as first step

I have installed tcpdump and I can see ICMP packets that are arriving [ping] IPTABLES is ALL enabled [iptables] But I do not get ping response. I have tried to connect to 502 port, and I also have seen the packets. But the app client in my PC couldn´t connect.

[SOLVED]Can´t reach a port listening vía rmnet0 interface

Legato Application Framework

jyijyi November 28, 2022, 9:45am 8

is it only working on 2G network?

You can capture wireshark log and see if there is any clue.

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[SOLVED]Can´t reach a port listening vía rmnet0 interface

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