Nmap facts for kids

Quick facts for kids
Nmap Security Scanner

Nmap scan results
Original author(s)	Gordon Lyon (Fyodor)
Initial release	September 1997; 27 years ago (1997-09)
Stable release	7.95  / Error: first parameter is missing. ()
Written in	C, C++, Python, Lua
Operating system	Cross-platform
Available in	English
Type	Network security
License	NPSL or modified GPLv2 or proprietary

Nmap (which stands for Network Mapper) is a special tool used to explore computer networks. It was created by a person known as Fyodor. Nmap helps you find devices and services connected to a network. It does this by sending out small pieces of data, called packets, and then checking the replies.

Nmap can do many things to check out computer networks. It can find active devices and figure out what kind of services they offer. It can also guess what operating system a device is using. Nmap can even adjust how it works if the network is slow or busy. This makes it a very smart tool for network discovery.

Nmap first started as a program for Linux computers. Later, it was made to work on other systems too. These include Windows, macOS, and BSD. It is still most popular on Linux, but many people use it on Windows as well.

What Nmap Can Do

Nmap has many cool features that help people understand networks better. Here are some of the main things it can do:

• Find Devices: It can discover which computers or devices are online. For example, it can list devices that respond to certain requests.
• Scan Ports: Nmap can check for open "doors" on target devices. These doors are called ports. Finding open ports helps identify services running.
• Detect Versions: It can figure out the name and version number of programs running on remote devices. This helps identify what software is being used.
• Ping Scan: This feature checks if a device is active by sending a simple "ping" message. It's like saying "hello" to see if anyone answers.
• Identify Operating Systems: Nmap can guess the operating system of network devices. It does this by looking at how the device responds to network activity.
• Run Scripts: You can use special scripts with Nmap to do more advanced tasks. These scripts can find security weaknesses or gather more details.

Nmap can also give you more information about devices. This includes their internet names (DNS), what type of device they are, and their unique hardware addresses (MAC address).

Common Uses for Nmap

People use Nmap for many different reasons. Here are some typical ways it is used:

• Check Security: It helps to see how secure a device or firewall is. It shows which connections can be made to it.
• Prepare for Audits: Before checking a system's security, Nmap can find open ports. This helps in knowing where to look for problems.
• Manage Networks: Nmap is great for keeping track of devices on a network. It helps create maps of the network and manage its parts.
• Find New Servers: It can help find new servers on a network. This is important for keeping the network secure.
• Measure Response Time: Nmap can send traffic to devices and measure how quickly they respond.
• Find Weaknesses: It can help find and use security weaknesses in a network.
• DNS Queries: Nmap can perform DNS queries and search for subdomains.

How You Can Use Nmap

Nmap can be used in different ways, either through text commands or with a visual program.

Graphical Interfaces

Nmap used to have an official visual program called NmapFE. This program showed results in a window, making it easier to use. Later, a new official program called Zenmap was created. Zenmap is also a graphical user interface (GUI). It lets you control Nmap and see the results in a clear, visual way.

There are also websites that let you control Nmap or look at its results using a web browser.

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  Zenmap, showing results for a port scan against Wikipedia

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  NmapFE, showing results for a port scan against Wikipedia

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  XNmap, a Mac OS X GUI

Nmap's Output Formats

Nmap can show its results in four different ways. All these results can be saved to a file, except for the interactive one. You can use other programs to change how Nmap's output looks. This helps you make custom reports.

• Interactive: This is what you see on your screen as Nmap is running. It updates in real-time. You can type options during the scan to watch its progress.
• XML: This format is like a structured document. Other computer tools can easily read and process it. You can even turn it into a web page (HTML) report.
• Grepable: This output is made for simple text-processing tools. It shows results in a way that's easy to search through line by line.
• Normal: This is the same as the interactive output, but it's saved to a file.
• Script Kiddie: This is a fun way to show the interactive output. It changes letters into numbers that look similar. For example, "Interesting ports" becomes "Int3rest1ng p0rtz". This style is called Leet.

Nmap's Journey Through Time

Nmap was first shared in September 1997 in a magazine called Phrack Magazine. The magazine even included the program's code. With help from people in the computer security community, Nmap kept getting better.

Over the years, Nmap added many new features. These included guessing operating systems and service types. The code was also rewritten from C to C++. Nmap also gained new ways to scan and support for different network rules, like IPv6. New programs were also added to work with Nmap.

Key Moments in Nmap's History

Nmap's License

Nmap was first given out under a license called the GNU General Public License (GPL). This license means people can freely use, change, and share the software. Later, Nmap's creators added some clearer rules to their license.

Starting with version 7.90, Nmap began using a new special license called NPSL. For a few versions, it was available under both the old and new licenses. This new license is a bit different from the original GPL.

Nmap in Schools and Learning

Nmap is a very important tool in schools and for learning about computers. It has been used in many studies about how networks work. It helps people understand the TCP/IP rules that computers use to talk to each other. Besides being a tool for research, Nmap itself has become a topic that people study and write about.

Images for kids

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  Nmap scan results

See also

In Spanish: Nmap para niños