Nmap Cheat Sheet 2024: All the Commands & Flags

Nmap Cheat Sheet

The one downside to a tool as robust and powerful as Nmap is remembering so many commands. Even many seasoned industry professionals fail to make the most of Nmap simply because keeping track of all its flags can prove such a challenge.

We have compiled and organized this Nmap cheat sheet to help you master what is arguably the most useful tool in any penetration tester’s arsenal. Whether you use it to memorize Nmap’s options, as a quick reference to keep nearby, or as a study sheet for your CEH/Pentest+ exam, we’re certain it will help you become a Nmap pro.

Download your own copy of this cheat sheet here. Now, let’s get to the Nmap commands.

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Target Specification

nmap a single IP
nmap specific IPs
nmap a range
nmap scanme.nmap.orgScan a domain
nmap using CIDR notation
-iLnmap -iL targets.txtScan targets from a file
-iRnmap -iR 100Scan 100 random hosts
-excludenmap -exclude listed hosts

Nmap Scan Techniques

-sSnmap -sSTCP SYN port scan (Default)
-sTnmap -sTTCP connect port scan (Default without root privilege)
-sUnmap -sUUDP port scan
-sAnmap -sATCP ACK port scan
-sWnmap -sWTCP Window port scan
-sMnmap -sMTCP Maimon port scan

Host Discovery

-sLnmap -sLNo Scan. List targets only
-snnmap -snDisable port scanning. Host discovery only.
-Pnnmap -PnDisable host discovery. Port scan only.
-PSnmap -PS22-25,80TCP SYN discovery on port x.
Port 80 by default
-PAnmap -PA22-25,80TCP ACK discovery on port x.
Port 80 by default
-PUnmap -PU53UDP discovery on port x.
Port 40125 by default
-PRnmap -PRARP discovery on local network
-nnmap -nNever do DNS resolution

Nmap Command Generator

Say goodbye to the hassle of trying to remember the exact syntax for your Nmap commands! With our Nmap Command Generator, you can simply say what you need Nmap to do and we will generate the command for you.

Port Specification

-pnmap -p 21Port scan for port x
-pnmap -p 21-100Port range
-pnmap -p U:53,T:21-25,80Port scan multiple TCP and UDP ports
-pnmap -p-Port scan all ports
-pnmap -p http,httpsPort scan from service name
-Fnmap -FFast port scan (100 ports)
-top-portsnmap -top-ports 2000Port scan the top x ports
-p-65535nmap -p-65535Leaving off initial port in range makes the scan start at port 1
-p0-nmap -p0-Leaving off end port in range
makes the scan go through to port 65535

Service and Version Detection

-sVnmap -sVAttempts to determine the version of the service running on port
-sV -version-intensitynmap -sV -version-intensity 8Intensity level 0 to 9. Higher number increases possibility of correctness
-sV -version-lightnmap -sV -version-lightEnable light mode. Lower possibility of correctness. Faster
-sV -version-allnmap -sV -version-allEnable intensity level 9. Higher possibility of correctness. Slower
-Anmap -AEnables OS detection, version detection, script scanning, and traceroute

OS Detection

-Onmap -ORemote OS detection using TCP/IP stack fingerprinting
-O -osscan-limitnmap -O -osscan-limitIf at least one open and one closed TCP port are not found it will not try OS detection against host
-O -osscan-guessnmap -O -osscan-guessMakes Nmap guess more aggressively
-O -max-os-triesnmap -O -max-os-tries 1Set the maximum number x of OS detection tries against a target
-Anmap -AEnables OS detection, version detection, script scanning, and traceroute

Timing and Performance

-T0nmap -T0Paranoid (0) Intrusion Detection System evasion
-T1nmap -T1Sneaky (1) Intrusion Detection System evasion
-T2nmap -T2Polite (2) slows down the scan to use less bandwidth and use less target machine resources
-T3nmap -T3Normal (3) which is default speed
-T4nmap -T4Aggressive (4) speeds scans; assumes you are on a reasonably fast and reliable network
-T5nmap -T5Insane (5) speeds scan; assumes you are on an extraordinarily fast network

Timing and Performance Switches

-host-timeout <time>1s; 4m; 2hGive up on target after this long
-min-rtt-timeout/max-rtt-timeout/initial-rtt-timeout <time>1s; 4m; 2hSpecifies probe round trip time
-min-hostgroup/max-hostgroup <size<size>50; 1024Parallel host scan group sizes
-min-parallelism/max-parallelism <numprobes>10; 1Probe parallelization
-max-retries <tries>3Specify the maximum number of port scan probe retransmissions
-min-rate <number>100Send packets no slower than <number> per second
-max-rate <number>100Send packets no faster than <number> per second

NSE Scripts

-sCnmap -sCScan with default NSE scripts. Considered useful for discovery and safe
-script defaultnmap -script defaultScan with default NSE scripts. Considered useful for discovery and safe
-scriptnmap -script=bannerScan with a single script. Example banner
-scriptnmap -script=http*Scan with a wildcard. Example http
-scriptnmap -script=http,bannerScan with two scripts. Example http and banner
-scriptnmap -script "not intrusive"Scan default, but remove intrusive scripts
-script-argsnmap -script snmp-sysdescr -script-args snmpcommunity=admin script with arguments

Useful NSE Script Examples

nmap -Pn -script=http-sitemap-generator scanme.nmap.orghttp site map generator
nmap -n -Pn -p 80 -open -sV -vvv -script banner,http-title -iR 1000Fast search for random web servers
nmap -Pn -script=dns-brute domain.comBrute forces DNS hostnames guessing subdomains
nmap -n -Pn -vv -O -sV -script smb-enum*,smb-ls,smb-mbenum,smb-os-discovery,smb-s*,smb-vuln*,smbv2* -vv SMB scripts to run
nmap -script whois* domain.comWhois query
nmap -p80 -script http-unsafe-output-escaping scanme.nmap.orgDetect cross site scripting vulnerabilities
nmap -p80 -script http-sql-injection scanme.nmap.orgCheck for SQL injections

Firewall / IDS Evasion and Spoofing

-fnmap -fRequested scan (including ping scans) use tiny fragmented IP packets. Harder for packet filters
-mtunmap -mtu 32Set your own offset size
-Dnmap -D,,, scans from spoofed IPs
-Dnmap -D decoy-ip1,decoy-ip2,your-own-ip,decoy-ip3,decoy-ip4 remote-host-ipAbove example explained
-Snmap -S www.microsoft.com www.facebook.comScan Facebook from Microsoft (-e eth0 -Pn may be required)
-gnmap -g 53 given source port number
-proxiesnmap -proxies, connections through HTTP/SOCKS4 proxies
-data-lengthnmap -data-length 200 random data to sent packets

Example IDS Evasion command

nmap -f -t 0 -n -Pn --data-length 200 -D,,,


-oNnmap -oN normal.fileNormal output to the file normal.file
-oXnmap -oX xml.fileXML output to the file xml.file
-oGnmap -oG grep.fileGrepable output to the file grep.file
-oAnmap -oA resultsOutput in the three major formats at once
-oG -nmap -oG -Grepable output to screen. -oN -, -oX - also usable
-append-outputnmap -oN file.file -append-outputAppend a scan to a previous scan file
-vnmap -vIncrease the verbosity level (use -vv or more for greater effect)
-dnmap -dIncrease debugging level (use -dd or more for greater effect)
-reasonnmap -reasonDisplay the reason a port is in a particular state, same output as -vv
-opennmap -openOnly show open (or possibly open) ports
-packet-tracenmap -T4 -packet-traceShow all packets sent and received
-iflistnmap -iflistShows the host interfaces and routes
-resumenmap -resume results.fileResume a scan

Helpful Nmap Output examples

nmap -p80 -sV -oG - -open | grep openScan for web servers and grep to show which IPs are running web servers
nmap -iR 10 -n -oX out.xml | grep "Nmap" | cut -d " " -f5 > live-hosts.txtGenerate a list of the IPs of live hosts
nmap -iR 10 -n -oX out2.xml | grep "Nmap" | cut -d " " -f5 >> live-hosts.txtAppend IP to the list of live hosts
ndiff scanl.xml scan2.xmlCompare output from nmap using the ndif
xsltproc nmap.xml -o nmap.htmlConvert nmap xml files to html files
grep " open " results.nmap | sed -r ‘s/ +/ /g’ | sort | uniq -c | sort -rn | lessReverse sorted list of how often ports turn up

Miscellaneous Nmap Flags

-6nmap -6 2607:f0d0:1002:51::4Enable IPv6 scanning
-hnmap -hnmap help screen

Other Useful Nmap Commands

nmap -iR 10 -PS22-25,80,113,1050,35000 -v -snDiscovery only on ports x, no port scan
nmap -PR -sn -vvArp discovery only on local network, no port scan
nmap -iR 10 -sn -tracerouteTraceroute to random targets, no port scan
nmap -sL -dns-server the Internal DNS for hosts, list targets only
nmap --packet-traceShow the details of the packets that are sent and received during a scan and capture the traffic.

You are only doing yourself a disservice by failing to learn and utilize all of Nmap’s features. It is the first go-to tool you will use in the scanning and enumeration stage of many assessments, setting the foundation for the rest of your pentest. 

Keep a copy of this Nmap cheat sheet to refer back to, and consider our Complete Nmap Ethical Hacking Course. It, and many other ethical hacking courses, are available in our VIP Member’s Section.

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  • Nathan House

    Nathan House is the founder and CEO of StationX. He has over 25 years of experience in cyber security, where he has advised some of the largest companies in the world. Nathan is the author of the popular "The Complete Cyber Security Course", which has been taken by over half a million students in 195 countries. He is the winner of the AI "Cyber Security Educator of the Year 2020" award and finalist for Influencer of the year 2022.

  • J says:

    THANK YOU!!! I used to use Legion but for some reason the frontend is proving unreliable, so I need to put on my big boy pants and use Nmap the proper way.

  • Raja says:


  • Mike says:

    Thank you! It’s content like this that helps make the membership cost worth it. Don’t get me wrong, the sheer content on the website makes it worth the cost but this stuff is just icing on the cake!

  • Mike QAAssuming an attacker runs the following command on nmap: “nmap –A –T3 –S –p-”. What does the attacker try to achieve? says:

    nmap –A –T3 –S –p-

  • Syam says:

    Thanks a ton. It is very useful.

  • Mikael says:

    Solved problem

  • James says:

    Very good informations, Thanks a lot.

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