Cfxtrjtrk

This is a fairly narrow issue, but I'm hoping the Ubuntu group can help. I asked on SO, but I am fairly sure the error I am getting is due to a missing setting in Ubuntu or an issue with my router port. I don't know how to debug this.

I installed Mosquitto on my Ubuntu 18.04 system. It operates on port 1883 by default. You can specify the exact port either on the command line or in the config file. I've tried many variations:

I opened port 1883 in the firewall via the ufw. That seems correct:

mark_admin:~$ sudo ufw status

Status: active    

To                         Action      From

--                         ------      ----

1883                       ALLOW       Anywhere                  

5900                       ALLOW       Anywhere                  

1883 (v6)                  ALLOW       Anywhere (v6)             

5900 (v6)                  ALLOW       Anywhere (v6)             

I am able to connect to it from another computer on the local network. But when I try to open a connection from the "outside world" using the computer's actual IP address, I get a "No connection could be made because the target machine actively refused it" Error.

I forwarded the port in my router (a TP-Link AC1200).
TP-LINK PORT FORWARDING

I'm not sure how to trace this to ground...

Has anyone successfully run Mosquitto Server and had connections coming in on Ubuntu 18.04?

Is there anyway I can test the port to see if it is allowing traffic to come in via the internet?

I am assuming that your server has internet access.

If you can get to the port on the local network, then the problem is definitely with the port forwarding.

First, does your server machine have a static IP address inside the network? If not, I highly recommend getting that fixed first. The reason for this is that when you set up a port forward, it will want to know what internal (192.168.0.x range) address to forward to. But if your server is Dynamic (using DHCP) then it will occasionally move, and every time it does, it will break the port forwarding.

Second, looking at your screenshot of the port forwarding settings, it mostly looks good, EXCEPT, it has 192.168.0.144, which is different than the 192.168.0.155 listed in the comments on the question. Make sure you fix that.

Third, where are you testing connecting with the outside address (96.221.154.134)? If it is from behind the same router, unless your router supports "hairpin NAT" (which most consumer routers don't) then it will not work. But it will work for everyone else "out on the internet" (IE, people not behind the same router). So it could be all working, and just how you are testing it could be broken. Obviously, if you are behind the same router, you should just use the internal address instead of the public address (if possible, IE, you aren't using DNS names that answer with the same address regardless of what router you are behind).

If there is anything not making sense, please, comment on this answer, and I'll try to help you further.