Network Mapper (Nmap) has become an indispensable network security tool for system administrators and cybersecurity professionals.
Over 300,000 active users leverage Nmap on a regular basis for tasks like network inventory, service monitoring, penetration testing, and more. And with good reason…
Nmap provides tremendous visibility into network infrastructure through flexible, fast, and highly accurate discovery scans.
From identifying all active hosts in a subnet to detecting hidden servers and sensitive data, Nmap enlightens like no other tool.
However, fully utilizing Nmap‘s more advanced functions takes dedication. There are over 400 scan options across host discovery, port scanning, operating system detection, scripting, formatting, and timing.
Memorizing every niche command is unrealistic for most. This is where Nmap cheat sheets can help admins better leverage scans to protect infrastructure.
Having a handy Nmap command reference speeds locating the best scan for a given task. Whether looking to:
- Find unauthorized or misconfigured devices
- Catalog servers for compliance audits
- Monitor network user activity
- Detect vulnerable versions and services
- Integrate with other security tools
- Automate asset discovery
- And much more…
Nmap cheat sheets bridge knowledge gaps to make networks more visible and secure.
This guide collects 10 of the very best Nmap cheat sheets and command references available in 2023. I evaluated each across several criteria:
- Comprehensiveness – Does it cover common and advanced commands?
- Clarity – Are descriptions and examples easy to follow?
- Presentation – Is it readable and well-organized?
- Portability – Can it be accessed offline?
- Specialization – Does it target beginners or experts?
Based on these standards, the top Nmap cheat sheets are:
1. StationX: The Gold Standard for Cross-Functional Excellence
StationX‘s widely referenced Nmap cheat sheet tops the list for its versatility. Creator Nathan House blends the right mix of commands for infrastructure scans, pen testing and beyond.
Colorized content, descriptive language, and practical examples really connect the dots for novice and seasoned admins alike. Whether looking to:
- Discover All Network Devices –
nmap -sn 192.168.1.1/24 - Detect Firewall Rules –
nmap -sA 192.168.1.1 - Fuzzy Scan for Hidden Hosts –
nmap -Pn -T4 -p- -A -v 192.168.1.* - Banner Grab from DNS Server –
nmap -sV --script=dns-zone-transfer.nse dns-server
It‘s all covered and more. Download the PDF for quick lookups without Internet access.
Pros: Broad, beginner friendly, nicely formatted
Cons: Light on advanced scripting
2. TutorialsPoint: Thorough and Authoritative
Living up to their name, TutorialsPoint‘s cheat sheet offers tremendous how-to context around command usage.
Sections on "Nmap Basics for Beginners" and "Advanced Tips & Tricks" guide newer users on best practices for infrastructure or risk scans. Implementation guidance around:
- Firewall Evasion – fragment packets, use decoy IP, obscure service
- Web App Scans – find ports, grab headers, crawl links
- Windows Auditing – detect LM/NTLM, SMB signing status
It‘s like an interactive Nmap crash course. The downside? At 6 pages it loses concise lookup convenience. Bookmark favorite sections.
Pros: Outstanding direction for beginners
Cons: Longer length loses quick reference utility
3. cs.lewisu.edu: The Ultra-Portable Pocket Guide
For admins needing a practical and portable command sampler, cs.lewisu.edu delivers.
Creator Yuval Nativ squeezes tons of functionality onto a standard sheet of paper. Find key commands for:
- Host Discovery –
nmap -P0 <target> - Port Scanning –
nmap -p 1-65535 -T4 <target> - Version Detection –
nmap -A <target> - Script Scanning –
nmap --script vuln <target>
It omits edge case uses but nails universally helpful scans. Plus the PDF fits nicely alongside keyboard for quick peeks. For power users, print multiples for bags, lockers, cubicles.
Pros: Extremely compact, printable, handy staple commands
Cons: Advanced scripts and switches excluded
4. Infosecsanyam.medium.com: Nmap 101 + Cheat Sheet
Readers with zero Nmap experience should start at Infosecsanyam‘s Nmap Guide.
Creator Sanyam Chawla builds an excellent foundation covering:
- TCP/IP, UDP, and Packet Flows
- Ping Sweeps, Port Scans, and Scan Types
- Host Discovery, Port Specification, and Scan Outputs
This base context informs effective command implementation like:
- ICMP Network Scan –
nmap -sn 192.168.1.1/24 - TCP SYN Stealth Scan –
nmap -sS 192.168.1.1 - UDP Scan on Top 1,015 Ports –
nmap -sU --top-ports 1015 192.168.1.1
I appreciate the layered learning approach. Use sections applicable to expertise level.
Pros: Flawless beginner resource
Cons: Light on advanced commands
5. GitHub: Open-Source Scanning for Developers
Those leveraging Nmap within software projects should follow Jason Bauer‘s Github Guide.
Beyond standard scan types, his cheat sheet dives deep on:
- Script Usage – seamless integration and execution
- Output Customization – match reports to audience needs
- Scan Comparison – track network changes between scans
- Firewall Evasion – sneak past packet filters
For developers building on Nmap programmatically, this cheat sheet bridges knowledge gaps. Contribute edits if any commands are missing.
Pros: Excellent for coders/advanced users
Cons: Very technical, lacks context
6. Comparitech: When Nmap Meets Nessus
Vulnerability scanner Nessus and Nmap are better together. This cheat sheet from Comparitech combines both toolsets.
Use Nmap for wider network reconnaissance like:
- Host Discovery – find all live devices
- Port Scanning – check for common vulnerabilities
- Service Fingerprinting – banner grab HTTP, DNS, SMB
Then leverage Nessus to deeply probe vulnerabilities like:
- Misconfigurations – default accounts, unnecessary services
- Unpatched Software – CVEs in OSes, apps, databases
- Encryption Issues – broken SSL, use of deprecated TLS
Together they audit assets better. Use the PDF for searchable future lookups.
Pros: Marries Nmap and Nessus perfectly
Cons: Overkill if only using Nmap
7. Hakin9: Your Pentest Arsenal
Penetration testers are power Nmap users by necessity. Check out Hakin9‘s cheat sheet for excellent scan examples like:
- ICMP Timestamp Probe –
nmap -PP -PS -PA <target> - FTP Bounce Scan –
nmap --ftp-bounce <intermediate FTP> --traceroute <target> - SMTP Open Relay Check –
nmap --script smtp-open-relay <smtp server>
It omits basics to focus exclusively on scans supporting professional security evaluations and red team engagements.
Pros: Purpose built for pen testers
Cons: Light on fundamentals
8. Networkstraining.com: Getting By With a Little NSE
The power of Nmap Scripting Engine (NSE) can‘t be overstated for automated scanning.
Networkstraining‘s cheat sheet shows off the possibilities like:
- Web App Scans – find ports, grab headers, crawl links
- Windows Auditing – check LLMNR, SMB signing status
- Mail Server Checks – SMTP user enum, server security
- Policy Compliance – CIS benchmark scans
I appreciate the focus on scripting plus a companion usage guide for help on more complex scans.
Pros: Perfect for mastering NSE scripts
Cons: Light on fundamentals
9. AllAboutTesting: Keeping Scans Simple
For users that just need a clean and simple command reference, check AllAboutTesting‘s Cheat Sheet.
The visual presentation simplifies lookups for:
- Host Specification – target IPs, ranges, networks
- Port Scanning – well-known ports, full/partial scans
- Service Detection – banner grabbing, version enumeration
- Operating System ID – find OSes down to Linux kernel
This sheet delivers straight forward answers when you just need a command.
Pros: Excellent quick reference
Cons: Extremely basic content
Rounding out the list, Steflan-Security.com fits lots of functionality into a tiny one-page guide.
Sections on scan types, timing options, target specs, scripting, and output formats make it very handy for:
- CIDR Scanning –
nmap 192.168.1.0/24 - UDP Scans –
nmap -sU IP_address - Vuln Scanning –
nmap --script vuln IP_address - Grep-able Output –
nmap -oG IP_address > results.txt
This hits all the highlights for seasoned admins minus depth. Add it to your browser bookmarks.
Pros: Extremely portable
Cons: Lacks examples/context
Additional Nmap Scope Considerations
While these cheat sheets capture most common use cases, truly leveraging Nmap‘s capabilities requires some additional scope context I want to cover quickly:
The Threat Landscape
From ransomware gangs like Conti crippling healthcare networks to nation-state groups like APT41 stealing intellectual property – the cyber threat spectrum continually expands.
Nmap sits at the foundation of monitoring these threats by cataloging perimeter devices, spotting misconfigurations like default services/accounts, identifying unpatched services prone to exploitation, and automating asset discovery.
Frankly, organizations can‘t defend infrastructure they don‘t understand or monitor. Nmap prevents blindspots.
Compliance and Regulations
Industries like finance and healthcare now face stringent cybersecurity compliance standards requiring documented proof of asset management programs, vulnerability management, and configuration monitoring.
Utilizing Nmap for quarterly or monthly network scans handles many of these requirements while surfacing risks in areas like encryption, authentication, and patching.
Common regulations benefiting from routine Nmap use include PCI DSS, HIPAA, SOX, GLBA, and many state privacy laws.
Incident Response
During security incidents like data theft or ransomware, time matters.
Nmap speeds incident responders scoping impacted assets, identifying entry points, and determining what got compromised.
Common use cases include credential dumping to spot compromised accounts, finding patient zero via scan comparison, and privilege escalation checks.
Network Inventory
With hardware lifecycles spanning 3-5 years, plus users added/removed monthly – keeping network maps updated manually is impossible.
Scheduled Nmap scans build accurate live asset inventories detailing servers, end user machines, printers, networked medical devices, shadow IT, etc.
Centralizing this data improves purchasing, tech refresh planning, license management, and decommissioning.
Tool Integration
While Nmap provides unparalleled network visibility independently, performance shoots even higher when integrating scan results into other systems.
Exporting data to security information and event management (SIEM) gives 24/7 monitoring and correlation with other threat signals.
Meanwhile, ingesting Nmap findings into vulnerability scanners like Nessus or Qualys automatically verifies risks across assets.
The use cases for consuming Nmap data continue expanding – don‘t silo it!
Getting Commanding with Nmap Scripting Engine (NSE)
Before closing, I want to highlight my favorite part of Nmap – Scripting Engine (NSE).
As hinted at on a few cheat sheets earlier, NSE allows creating custom scripts extending Nmap functionality.
Whether looking to:
- Audit configurations against benchmarks
- Crawl web apps for debug pages or files
- Check mail servers for open relays
- Test authentication mechanisms
- Identify vulnerable services like Heartbleed or BlueKeep
- Or WANT ANY UNIQUE EXAMPLES?
Scripting solves the problem.
The Nmap Scripting Engine (NSE) Guide provides a full reference manual to get started.
Below are just three examples demonstrating the immense value scripts add to scans:
NSE Example 1: Samba Config Auditor
This script checks for multiple misconfigurations in Samba file sharing that often expose data like shares without passwords.
nmap --script=smb-os-discovery.nse -p445 IPOutput quickly details issues for remediation like insecure guest accounts.
NSE Example 2: Heartbleed Detector
Finding services vulnerable to the Heartbleed OpenSSL bug which can leak passwords and sensitive data is trivial one liner.
nmap -sV -p 443 --script=ssl-heartbleed IPThis can run against ranges finding aged equipment communicating securely but running a vulnerable version of OpenSSL.
NSE Example 3: Stuxnet Detector
Wormable exploits like Conficker and Stuxnet require increased vigilance to spot. This script hunts:
nmap --script stuxnet-detect -p445 IPOutput reports any hits for rapid isolation and investigation.
The nearly 600 NSE scripts bundled with Nmap and hundreds more contributed by the community transform scan capabilities. Learn more at https://nmap.org/nsedoc/!
In closing, I hope this breakdown of the top 10 Nmap cheat sheets helps better protect your organization by improving network visibility and security posture.
Bookmarking or printing a handy Nmap command reference guide pays security dividends through faster asset discovery, misconfiguration detection, and vulnerability assessments.
As with any powerful technology, remember to utilize Nmap ethically and legally with permission.
But don‘t let that stop you from unleashing Nmap‘s full potential! Master Nmap and master network security visibility.
