Red Hat

I uses iptables but not working

Could you be a bit more specific?

One can open ports through iptables even if they have no idea about the commands, chains, etc.
First, take a look at /etc/sysconfig/iptables file. You should see a line something like this:

Code:

-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

If you have opened the file in an editor, copy the line and paste it just below the above line. Now, you have to edit certain things like the port number and whether you are opening TCP or UDP port. Once done, save the file and restart iptables service. That's all.

Code:

service iptables restart
iptables -nL | grep PORT_NUMBER
netstat -tulpn | grep PORT_NUMBER