NMAP(Network Mapping) is one of the important network monitoring tool. Which checks for what ports are opened on a machine.
This brief tutorial is going to show you how to setup or configure a simple yet effective firewall rules for your systems. These rules also apply to Linux systems using iptables firewall. iptables is a simple firewall installed on most Linux systems by default. It’s used to allow or deny network communications in or out of a system.