Red Hat 7.3 firewall settings?

[safra]

Hi,

I asked this question on another linux board but no positive results after several posts.

This is the problem:

I am experimenting with a perl socket server. Locally everything works fine but I can not get access to the socket server from a remote system. I do get access to the html page with the embedded multi user application.

I think this has to do with a firewall security issue.

if I do:
nmap -sS -O localhost

the port I am using for the socket server is not on the list with open ports.

How can I open this specific port for all tcp traffic?

Others advised me to install firestarter, but this doesnot allow to open ports. Then they referred me to the files 'firewall.sh' and 'allow-all' but I have no idea what to put in those files.

Can anyone here guide me on how to open a port?

Thanks you,
Ron

 

[LarryTheCucumber]

Do you get any messages in /var/log/messages ?

 

[safra]

Yes, /var/log/messages contains data but as far as I can see nothing related to this.

Or do you mean some data in particular?
Ron

 

[LarryTheCucumber]

Try this:

tail -f /var/log/messages

This will show a continous display of the messages file.

Open your application and see what if anything shows up in the messages file. If it fails due to a port rejection it may/should show up in messages file.

 

[safra]

I tried this, the only message that keeps popping up is that of a sound module that can't be located (I haven't yet looked at that).

But I think I am getting closer. When I connect through localhost the ip of the user (output by the perl file) is 127.0.0.1

I connected through

http://127.0.0.1/socket.html

and this did work!

Then I tried some things like changing the host name in both the flash movie and the perl file into 127.0.0.1

Although I still can't connect through my real ip, the verification process in the Flash movie does work correct now as it says that connecting failed whereas before this remained completely silent.

There are still no messages of rejected ports.

Any ideas on this? Is it perhaps possible to automatically forward incoming requests for

http://xxx.xxx.xxx.xxx/socket.html

to

http://127.0.0.1/socket.html

or is this a stupid idea?

Thanks,
Ron

 

[LarryTheCucumber]

Look at the logs in /var/log/httd

Anything about connection failure in them?

 

[safra]

no, only some notice messages and error messages of not existing urls (because of me typing the wrong url).

 

[LarryTheCucumber]

Do you have the perl script registered in the mod_perl for apache?
This might not be the correct place butI haven't done any perl for apache in over a year so I'm very rusty.

 

[safra]

I have an average knowledge of perl. It seems this should be ok as the server is running fine locally, or not?

Meanwhile I thought I had fixed the problem because locally I managed to get it to work by using the absolute path

http://127.0.0.1/socket.swf

in the html file to access the flash movie. Accessing the html page through

http://my.real.ip.here/socket_server.html

and connecting to the socket did work correctly now!

I then tried to access the page through a remote machine but it didn't load the flash movie (there was no error message, but the loading bar showed very slow progress, after a minute or so I disconnected).

Is this an ip issue? As far as I know flash only permits connection to a socket of the same machine where the swf is located. The flash movie is accessed through my public ip. Could it be that the attempt to connect to the socket is treated as a connection to a different machine (the internal ip) by the flash movie?

If so, is there anything I can do about this through the apache server or so?

Ron,

 

[LarryTheCucumber]

I haven't work with flash. But a link requires the address of the server, not the loop back, other wise the remote system tries to access it's loop back. So the links should be http://[server address]/socket.swf
You can test links by creating a page and put a link to it in the beginning page.

 

[safra]

I managed to get it to work. Next to the port security issue, in my case for some reason it turned out that flash is very strict in how things are called.

After a lot of trial and error I found that, next to the absolute urls in calling the flash movie it is necessary that both in the flash movie and the perl server the connection is established by specifying the ip of the machine on which it is running and not by null or localhost as described in the flash manuals.

Larry, thanks a lot for all the help, you were very persistent .

regards,
Ron

 

[LarryTheCucumber]

Most of the time it's a matter of just talking through the problem that solves it.

YOu are welcome, this was fun.

 

[safra]

Well, I am glad to hear it was fun for you. Then at least one of us enjoyed himself!