Iptables – Open port 8082 on ubuntu for remote access

firewalliptables

I need to open port 8082 on my linux box for remote access. I can access the application on port 8082 locally, but not from my other box.

Ports 8080 and 8081 are accessible locally as well as remote. 8080 and 8081 have applications attached that were installed via apt-get, whereas 8082 has a program running from eclipse (own development).

I have seen How to open a 8080 port for an application, with iptables and others like that and followed the instructions, but still could not access 8082 remotely.

One interesting point is that, when doing

sudo iptables -L  --line-numbers

I only see my entries for port 8082, and nothing else!
Meanwhile I deleted those entries, too.

ufw status

gives "inactive".

This looks to me as if the old goods of firewalls and crossroads now have new names by which they must be summoned.

Question is, is there really a new set of commands for handling routing and firewall, if yes, how are they used, if no, why are the old commands not working?

Best Answer

Your application is most likely listening only to the localhost network interface, that is 127.0.0.1:8082, therefore it can be reached only from localhost.

You can check this by running netstat -lnp, and checking the Local address column corresponding to your software. If it is 127.0.0.1:8082, this is the reason and you need to change your software to listen to 0.0.0.0:8082 or :::8082.

Related Solutions

Linux – How to open port 10011 in centos using iptables

Don't start by using a website to check if that port is open.

Start with your local system:
```
$ netstat -tln
```
This should you all listening ports on your system. Do you see an entry for port 10011? It will look something like:
```
tcp        0      0 0.0.0.0:10011               0.0.0.0:*                   LISTEN      
```
If you don't see that, you've got a problem. If you do see that, move on to the next step:
Use telnet to try connecting to the local port to make sure a locally originated connection works. Try this:
```
$ telnet localhost 10011
```
If something is listening on that port, this should report:
```
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
```
If instead it reports:
```
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
```
Then you probably have a problem with the application.
Is local connectivity working? Great! Now you should ideally perform the same test from another host on your local network:
```
$ telnet a.b.c.d 10011
```
Where a.b.c.d is the ip address of your system. If this fails, you probably have a local firewall problem. If it works, move on to step 4.
If connectivity on the local network is working, the remaining possibility is that there is a router or firewall between you and the outside world that is configured to block inbound traffic. Do you control your network connectivity? Does someone else? Verify that your network gateway will pass the traffic.

If this doesn't help out, let us know what fails and we'll work from there.

Iptables – Cannot connect on open port

It seems, Tomcat listens on IPv6 only. May be you missed something during installation?

Check this link for further information: https://confluence.atlassian.com/display/JIRAKB/How+to+run+JIRA+on+a+specific+IP

Best Answer

Related Solutions

Linux – How to open port 10011 in centos using iptables

Iptables – Cannot connect on open port

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