Nmap (“Network Mapper”) is an free open source utility for network exploration, administration, and security auditing. It uses IP packets in novel ways to determine which hosts are available online (host discovery), which TCP/UDP ports are open (port scanning), and what applications and services are listening on each port (version detection). It can also identify remote host OS and device types via TCP/IP fingerprinting. Nmap offers flexible target and port specifications, decoy/stealth scanning for firewall and IDS evasion, and highly optimized timing algorithms for fast scanning. Nmap runs on all popular operating systems, including Linux, Windows, Mac OS X, FreeBSD, Solaris, and OpenBSD. Download command-line or graphical versions of Nmap and its documentation from Insecure.Org. There are many substantial changes after the previous stable release 3.50 and it is recommended to install the new version. Are there any other tools that your would recommend for securing your system?