<div>
Redhat 7.2 sets up an iptables-based firewall for you automatically during installation. To open a tcp port use something like:<br />
<br />
iptables -A INPUT -s &lt;source-ip/wildcard&gt; -p tcp -m tcp --dport &lt;port-number&gt; -j ACCEPT<br />
<br />
<a href="http://unixhelp.ed.ac.uk/CGI/man-cgi?iptables" rel="ugc">http://unixhelp.ed.ac.uk/CGI/man-cgi?iptables</a>
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Redhat 7.2 sets up an iptables-based firewall for you automatically during installation. To open a tcp port use something like:

iptables -A INPUT -s <source-ip/wildcard> -p tcp -m tcp --dport <port-number> -j ACCEPT

http://unixhelp.ed.ac.uk/CGI/man-cgi?iptables [http://unixhelp.ed.ac.uk/CGI/man-cgi?iptables]

<div>
Try:<br />
&nbsp; netstat -ab<br />
or<br />
&nbsp; netstat -a<br />
if your unix distribution's netstat does not support the -b option.<br />

</div>


Try:
  netstat -ab
or
  netstat -a
if your unix distribution's netstat does not support the -b option.


<div>
iptables --list<br />
<br />
shows you which rules are setup<br />

</div>


iptables --list

shows you which rules are setup


<div>
<div class="content wysiwyg-content">
Hi,<br />
&nbsp;I would like to know which command to use to know the port information on a UNIX Box and I would like to know about the open ports and closed ports.<br />
Thanks<br />
Koppcha
</div>
</div>


Hi,
 I would like to know which command to use to know the port information on a UNIX Box and I would like to know about the open ports and closed ports.
Thanks
Koppcha

Open ports on UNIX

Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers. For large systems, the operating system makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system. Operating systems provide a software platform on top of which other programs, called application programs, can run.