If you prefer to have a GUI interface to manage your firewall, open or close ports, or track your security an effective option is ConfigServer’s CSF. This tool allows you to open and close ports and manage your firewall from the WHM. If you are adverse to editing the IPtables via SSH or the system console, then you’ll probably want to look into this.
ConfigServer’s installation instructions are pretty straight forward. You’ll want to access System Console and the WHM in order to use this.
rm -fv csf.tgz wget http://www.configserver.com/free/csf.tgz tar -xzf csf.tgz cd csf sh install.sh
Then you’ll test to see if you’ve got the right iptable modules
perl /usr/local/csf/bin/csftest.pl
From there go to your WHM, go to Plugins and then the ConfigServer Security plugin will be there and you can start using it. If you want to open or close ports you’d go to configure firewall and it’ll be there. Be sure to read up on how to use this tool before you dive into it though. There is a chance that you can cause harm to your server if you edit the wrong settings or turn off/on the wrong things.