1. Flexible : Supports dozens of advanced techniques for mapping out networks filled with IP filters, firewalls, routers, and other obstacles. This includes many port scanning mechanisms (both TCP & UDP), OS detection, version detection, ping sweeps, and more. See the documentation page.
2. Powerful : Nmap has been used to scan huge networks of literally hundreds of thousands of machines.
3. Portable : Most operating systems are supported, including Linux, Microsoft Windows, FreeBSD, OpenBSD, Solaris, IRIX, Mac OS X, HP-UX, NetBSD, Sun OS, Amiga, and more.
4. Easy : While Nmap offers a rich set of advanced features for power users, you can start out as simply as "nmap -v -A targethost". Both traditional command line and graphical (GUI) versions are available to suit your preference. Binaries are available for those who do not wish to compile Nmap from source.
5. Free : The primary goals of the Nmap Project is to help make the Internet a little more secure and to provide administrators/auditors/hackers with an advanced tool for exploring their networks. Nmap is available for free download free download, and also comes with full source code that you may modify and redistribute under the terms of the license.
6. Well Documented : Significant effort has been put into comprehensive and up-to-date man pages, whitepapers, tutorials, and even a whole book! Find them in multiple languages here.
7. Supported : While Nmap comes with no warranty, it is well supported by a vibrant community of developers and users. Most of this interaction occurs on the Nmap mailing lists. Most bug reports and questions should be sent to the nmap-dev list, but only after you read the guidelines. We recommend that all users subscribe to the low-traffic nmap-hackers announcement list. You can also find Nmap on Facebook and Twitter. For real-time chat, join the #nmap channel on Freenode or EFNet.
8. Acclaimed : Nmap has won numerous awards, including "Information Security Product of the Year" by Linux Journal, Info World and Codetalker Digest. It has been featured in hundreds of magazine articles, several movies, dozens of books, and one comic book series. Visit the press page for further details.
9. Popular : Thousands of people download Nmap every day, and it is included with many operating systems (Redhat Linux, Debian Linux, Gentoo, FreeBSD, OpenBSD, etc). It is among the top ten (out of 30,000) programs at the Freshmeat.Net repository. This is important because it lends Nmap its vibrant development and user support communities.

1. Host Discovery : Nmap begins by determining which hosts are active on the network by sending ICMP echo requests (ping) or scanning specific ports.
2. DNS Lookups : Once Nmap has identified active hosts, it can optionally perform reverse DNS lookups to map IP addresses to domain names. It can provide more meaningful and human-readable information in the scan results.
3. Port Scanning : After that, Nmap performs port scanning to determine which ports on the target hosts are open, closed, or filtered.
4. Service and Version Detection : After identifying open ports, Nmap tries to determine the type of services or applications running on those ports. It probes open ports to gather information about the versions of services running on those ports.
5. OS Detection : Nmap can also perform operating system detection. It sends specific packets and analyzes the responses to determine the OS of the target host.
6. Scripting and Vulnerability Scanning : Nmap supports scripting using the Nmap Scripting Engine (NSE), allowing for advanced scanning and vulnerability detection.

• Network inventory and mapping
• Security auditing and monitoring
• Network troubleshooting and diagnostics
• Firewall and network configuration verification
• Port scanning to identify open ports and services
• Vulnerability assessment and penetration testing
• Operating system detection to determine the target’s OS
• Investigating network anomalies and suspicious activities
• Service version detection to identify software and its versions

Nmap is a powerful network scanning and security auditing tool. Here are some key aspects of its usage :

Basic Scanning

1. Ping Scan : -sp option scans for live hosts on a network. Example : nmap -sp 192.168.1.1/24
2. Single Host Scan : -p option scans a single host for 1000 well-known ports. Example : nmap -p 192.168.1.1
3. Port Scanning : -p option scans for specific ports or a range of ports. Example : nmap -p 76-973 192.168.1.1

Advanced Scanning

1. Stealth Scanning : -sS option performs a stealth scan by sending SYN packets and analyzing responses. Example : nmap -sS 192.168.1.1
2. Version Scanning : -sV option detects application versions and operating systems. Example : nmap -sV 192.168.1.1
3. OS Detection : -O option detects operating systems. Example : nmap -O 192.168.1.1

Scripting and Automation

1. Nmap Scripting Engine (NSE) : allows writing scripts for automating networking tasks and penetration testing.
2. Lua Programming Language : used to modify existing scripts or write custom ones.

Exporting Results

1. Verbose Output : -v option provides detailed information about the scan process.
2. Text File Export : -oN option exports scan results to a text file. Example : nmap -oN output.txt 192.168.1.1
3. XML Export : -oX option exports scan results to XML format. Example : nmap -oX output.xml 192.168.1.1
4. Multi-Format Export : -oA option exports scan results in multiple formats (text, XML, and gnmap). Example : nmap -oA output 192.168.1.1

Additional Tips

1. Use the -h option to access Nmap’s built-in help command, which lists available flags and options.
2. Be cautious when scanning networks without permission, as this may trigger security alerts or be considered unauthorized access.
3. Use Nmap responsibly and only for legitimate purposes, such as network inventory, security audits, or penetration testing.

Examples

1. Scan a network for live hosts : nmap -sp 192.168.1.1/24
2. Scan a single host for 1000 well-known ports : nmap -p 192.168.1.1
3. Detect application versions and operating systems : nmap -sV 192.168.1.1
4. Export scan results to a text file : nmap -oN output.txt 192.168.1.1

• libc6
• libgcc-s1
• liblinear4
• liblua5.4-0
• libpcap0.8t64
• libpcre2-8-0
• libssh2-1t64
• libssl3t64
• libstdc++6
• nmap-common
• zlib1g

Terminal Installation Commands ...
GUI Installation Steps ...

Linux

1. Update Package Lists : Run :

$ sudo apt update # Debian-based

$ sudo dnf check-update # Fedora-based

2. Install Nmap :
• Debian-based (Ubuntu, Kali, etc.) : sudo apt install nmap -y
• Red Hat-based (Fedora, CentOS, RHEL) : sudo dnf install nmap -y
• Arch Linux : sudo pacman -S nmap
3. Verify Installation : nmap --version

Windows

1. Download the Installer : Get the latest Nmap setup file from the official website.
2. Run the Installer : Open the downloaded .exe file and follow the setup wizard.
3. Select Components : Ensure Zenmap GUI is selected during installation.
4. Complete Installation : Choose the installation directory and finish the setup.
5. Verify Installation : Open Command Prompt and run : nmap --version

MacOS

1. Install Nmap (Zenmap requires Nmap to function) : brew install nmap
2. Download Zenmap : Get the macOS package from the official website.
3. Install Zenmap : Follow the installation instructions provided on the website.
4. Launch Zenmap : Open the application and start scanning networks.

Terminal Uninstallation Commands ...
GUI Uninstallation Steps ...

Linux

1. Debian-based : sudo apt remove nmap -y
2. Red Hat-based : sudo dnf remove nmap -y
3. Arch Linux : sudo pacman -R nmap

Windows

1. Open Control Panel → Programs and Features.
2. Find Nmap, right-click, and select Uninstall.
3. Delete leftover files from C:\Program Files (x86)\Nmap.

MacOS

1. Remove Zenmap : Delete the application from the Applications folder.
2. Uninstall Nmap (if needed) : brew uninstall nmap
3. Remove Configuration Files : Manually delete any leftover files.