Linux firewall

For those who like to deploy a Linux firewall but lack the knowledge in IPTABLES here is a firewall generator for Linux IPTABLES. This is a quick and easy to use IPTABLES Linux firewall script generator.

These are the steps:

• Check for the run level of iptables.
  • chkconfig --list | grep iptables
• If the run levles are off then
  • chkconfig iptables on
• Go to this site's firewall generator
• Fill in the blanks :)
• Copy the scripts to a text editor in Linux.
• Change the permision of the file to 755
  • chmod 755 my_firewallscript.sh
• As root run the script
  • ./my_firewallscript.sh

• Save the new firewall rules
  • service iptables save

Thats it your new rules are saved and every time the system reboot the rules are automatically loaded.

Linux kernel parameters must also be edited to allow packet forwarding to clients. Edit sysctl.conf to allow forwarding of packets. After editing the file you may decide to reboot the system or do the command sysctl -p to reload the new kernel parameter(s) :).