Nmap, or Network Mapper, is a free, open-source tool published by the Free Software Foundation under the GNU General Public License. It is often used by network administrators and IT security professionals to scan enterprise networks, live hosts, specific services, or specific operating systems.
Part of Namp’s beauty is its ability to create IP packets from scratch and send them using specialized methods to perform the above types of scans and more. Additionally, Nmap comes with command-line or GUI functionality and makes it easy to install everything from Unix and Windows to Mac OS X. Installation requirements depend on the version of Nmap you are installing to, and it mainly includes network library dependencies.
In a great scheme of things, Nmap is relatively new to the small world at the age of 10. However, in Internet-terminology, Naps is practically a great-grandfather. This app was first released to the world by Fyodor in a 1997 frock article. His article includes the entire source code for the application, his code comments, interesting variables, and error messages.
As Nmap gained followers and began to show more interest, Fyodor Geek Fame was introduced into the developer-style. Proof of Namp’s fame is one of Fyodor’s most innovative films of all time: The Matrix. In the sequel, The Matrix Reloaded, one of the main characters pulls out the laptop, executes a perfect example for the Nampport scan, and then follows it up with SSH-based exploits.
Nmap Firewall is built with malicious ideas and always looks great on network and operating system updates that affect the scanning capabilities of the tool. Fyodor was actually verbally attacked by several administrators for continuing to improve and incorporate preventive measures in the application. In justifying the number, Fyodor’s attitude has always been supportive of the administrator. In the documentation and forum posting submitted by Foder, he explained that managers need to be one step ahead of attackers. He thinks attackers will find a way to scan your network, so why not you? As an example of trying to stay ahead of half of the challenges by 2004, Microsoft made some changes to its XP operating system with Service Pack (SP) 2, which affected the manufacturing process of raw sockets.
Since Nmap requires the ability to create and convert raw sockets to create and send packets, this greatly affects the Windows XP version of the tool. Foder and the developers working with him on Nmap reported all the changes and then started coding Nmap’s XP SP2-specific release to work around the barriers imposed by Microsoft. This type of response was first replicated when Fyodor discovered that many IDS tools had begun creating signatures to identify Namp scans based on the time and pattern used by different scan types. To defeat this, they introduced new timing capabilities and types of scans, including fragment packet capability, spoof source addresses, and craft packet options.