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	7.97  / 12 May 2025; 3 months ago (12 May 2025)
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 Gordon Lyon, or Fyodor. Nmap helps people find devices and services connected to a network. It does this by sending out small pieces of information, called packets, and then looking at the answers it gets back.

Nmap has many cool features for checking out computer networks. It can find out which devices are online and what services (like websites or email) they are running. It can even guess what kind of operating system a device is using. Nmap can also use special scripts to find more details, like if there are any weak spots in a system. It's smart enough to adjust how it works, even if the network is slow or busy.

Nmap first started as a tool for Linux computers. But now, you can use it on other systems too, like Windows, macOS, and BSD. It's still most popular on Linux, though.

What Nmap Can Do

Nmap has many useful features that help people understand networks better:

• Quick Scan: This is a fast way to check for basic open connections on a device.
• Finding Devices: Nmap can find all the active devices on a network. For example, it can list devices that respond to certain requests.
• Port Scanning: It can find out which "ports" are open on a device. Think of ports like doors on a house; if a door is open, a service might be running there.
• Version Detection: Nmap can figure out the name and version of programs running on remote devices.
• Ping Scan: This simply checks if a device is online by sending a "ping" message.
• Operating System Guessing: Nmap can often guess what operating system (like Windows or Linux) a device is running. It does this by looking at how the device responds to network messages.
• Scripting: Nmap has a special tool called the Nmap Scripting Engine (NSE). This lets users write small programs (scripts) using the Lua language. These scripts can do even more advanced checks, like finding security problems.

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 addresses).

Here are some common ways Nmap is used:

• Checking the security of a device or firewall. It helps see what connections can be made to it.
• Finding open ports on a device before doing a security check.
• Keeping track of devices on a network and managing them.
• Finding new servers on a network to make sure they are secure.
• Sending data to devices and measuring how fast they respond.
• Finding and fixing security weaknesses in a network.
• Looking up DNS information and finding related web addresses.

How You Can Use Nmap

Nmap has different ways you can use it. It used to have an official graphical tool called NmapFE. But now, the main graphical tool is called Zenmap. A graphical tool means you can click buttons and see things visually, instead of typing commands. Zenmap makes Nmap easier to use for many people.

Different Ways Nmap Shows Results

Nmap can show you the information it finds in four main ways. All of these, except for the interactive one, can be saved to a file. This means you can look at the results later or use other programs to work with them.

• Interactive: This is what you see right away when you run Nmap from your computer's command line. It updates as the scan happens.
• XML: This is a special format that other computer programs can easily read and understand. You can even turn it into a web page report.
• Grepable: This format is made for simple text tools. It helps you quickly search for specific information.
• Normal: This is just like the interactive output, but it's saved into a file for you to keep.
• Script Kiddie: This is a fun way to see the results. It changes letters into numbers that look similar, like "Interesting ports" becoming "Int3rest1ng p0rtz". This style is called Leet.

Nmap's Story

Nmap was first shared in September 1997. It appeared in a magazine called Phrack Magazine, and its computer code was included. With help from many people in the computer security world, Nmap kept getting better. New features were added, like guessing operating systems and services. The code was even rewritten to make it faster and more powerful. It also gained support for newer internet technologies.

Here are some important moments in Nmap's history:

• 1998: Nmap 2.00 was released, which could guess operating systems.
• 1999: NmapFE, the first graphical tool for Nmap, was included.
• 2000: Nmap became available for Windows computers.
• 2002: The main code of Nmap was rewritten from one programming language (C) to another (C++).
• 2003: The first public version that could detect service versions was released.
• 2005: Nmap was part of Google Summer of Code, a program where students help improve open-source software. This led to new features like Zenmap and the Nmap Scripting Engine.
• 2007: Nmap 4.50, the 10th Anniversary Edition, was released with Zenmap and the Nmap Scripting Engine.
• 2009: Nmap 5.00 was released, including new tools like Ncat (a replacement for netcat) and Ndiff (for comparing scan results).
• 2012: Nmap 6.00 came out with full support for IPv6, a newer internet address system.
• 2015-2020: Many more updates improved how Nmap finds operating systems and services. New scripts and tools were also added.

Nmap's License

Nmap was first shared under a license called the GNU General Public License (GPL). This license allows people to use, change, and share the software freely. Over time, Nmap's creators added some specific rules to their license to make things clearer.

Starting with version 7.90, Nmap began using a new license called NPSL. For a while, versions 7.90, 7.91, and 7.92 were available under both the old and new licenses. Some versions of Linux operating systems consider this new NPSL license to be "non-free," meaning it has more restrictions than the older GPL.

Nmap in Schools

Nmap is also used a lot in schools and universities. It's an important tool for studying how computer networks work and for research about the TCP/IP protocol suite, which is how computers talk to each other on the internet. Besides being a tool for research, Nmap itself has become a topic that researchers study!

See also

In Spanish: Nmap para niños