Iptables

A firewall utility in Linux systems to allow traffic or to block it. Iptables is designed to create, maintain and monitor the IP packet filter rules in the Linux kernel tables. This administration tool applies to IPv4 and decides the filtering of packets. It is a front-end tool that allows communication to the kernel. It uses the /etc/sysconfig/iptables file to save the rulesets. It is very flexible and it uses the chains like input, forward and output. Iptables command allows the system administrators to manage incoming and outgoing traffics.