Nmap Cheat Sheet

Basic Scanning Techniques

  • Scan a single target
    • nmap [target]
  • Scan multiple targets
    • nmap [target1,target2,etc]
  • Scan a list of targets
    • nmap -iL [list.txt]
  • Scan a range of hosts
    • `nmap [range of IP addresses]
  • Scan an entire subnet
    • nmap [IP address/cdir]
  • Scan random hosts
    • nmap -iR [number]
  • Excluding targets from a scan
    • nmap [targets] –exclude [targets]
  • Excluding targets using a list
    • nmap [targets] –excludefile [list.txt]
  • Perform an aggressive scan
    • nmap -A [target]
  • Scan an IPv6 target
    • nmap -6 [target]

Discovery Options

  • Perform a ping scan only
    • nmap -sP [target]
  • Don’t ping
    • nmap -PN [target]
  • TCP SYN Ping
    • nmap -PS [target]
  • TCP ACK ping
    • nmap -PA [target]
  • UDP ping
    • nmap -PU [target]
  • SCTP Init Ping
    • nmap -PY [target]
  • ICMP echo ping
    • nmap -PE [target]
  • ICMP Timestamp ping
    • nmap -PP [target]
  • ICMP address mask ping
    • nmap -PM [target]
  • IP protocol ping
    • `nmap -PO [target]
  • ARP ping
    • nmap -PR [target]
  • Traceroute
    • nmap –traceroute [target]
  • Force reverse DNS resolution
    • nmap -R [target]
  • Disable reverse DNS resolution
    • nmap -n [target]
  • Alternative DNS lookup
    • nmap –system-dns [target]
  • Manually specify DNS servers
    • nmap –dns-servers [servers] [target]
  • Create a host list
    • nmap -sL [targets]

Advanced Scanning Options

  • TCP SYN Scan
    • nmap -sS [target]
  • TCP connect scan
    • nmap -sT [target]
  • UDP scan
    • nmap -sU [target]
  • TCP Null scan
    • nmap -sN [target]
  • TCP Fin scan
    • nmap -sF [target]
  • Xmas scan
    • nmap -sX [target]
  • TCP ACK scan
    • nmap -sA [target]
  • Custom TCP scan
    • nmap –scanflags [flags] [target]
  • IP protocol scan
    • nmap -sO [target]
  • Send Raw Ethernet packets
    • nmap –send-eth [target]
  • Send IP packets
    • nmap –send-ip [target]

Port Scanning Options

  • Perform a fast scan
    • nmap -F [target]
  • Scan specific ports
    • nmap -p [ports] [target]
  • Scan ports by name
    • nmap -p [port name] [target]
  • Scan ports by protocol
    • nmap -sU -sT -p U:[ports],T:[ports] [target]
  • Scan all ports
    • nmap -p “*” [target]
  • Scan top ports
    • `nmap –top-ports [number] [target]
  • Perform a sequential port scan
    • nmap -r [target]

Version Detection

  • Operating system detection
    • nmap -O [target]
  • Submit TCP/IP Fingerprints
    • http://www.nmap.org/submit/
  • Attempt to guess an unknown
    • nmap -O –osscan-guess [target]
  • Service version detection
    • nmap -sV [target]
  • Troubleshooting version scans
    • nmap -sV –version-trace [target]
  • Perform a RPC scan
    • nmap -sR [target]

Timing Options

  • Timing Templates
    • nmap -T [0-5] [target]
  • Set the packet TTL
    • nmap –ttl [time] [target]
  • Minimum of parallel connections
    • nmap –min-parallelism [number] [target]
  • Maximum of parallel connection
    • nmap –max-parallelism [number] [target]
  • Minimum host group size
    • nmap –min-hostgroup [number] [targets]
  • Maximum host group size
    • nmap –max-hostgroup [number] [targets]
  • Maximum RTT timeout
    • nmap –initial-rtt-timeout [time] [target]
  • Initial RTT timeout
    • nmap –max-rtt-timeout [TTL] [target]
  • Maximum retries
    • nmap –max-retries [number] [target]
  • Host timeout
    • nmap –host-timeout [time] [target]
  • Minimum Scan delay
    • nmap –scan-delay [time] [target]
  • Maximum scan delay
    • nmap –max-scan-delay [time] [target]
  • Minimum packet rate
    • nmap –min-rate [number] [target]
  • Maximum packet rate
    • nmap –max-rate [number] [target]
  • Defeat reset rate limits
    • nmap –defeat-rst-ratelimit [target]

Firewall Evasion Techniques

  • Fragment packets
    • nmap -f [target]
  • Specify a specific MTU
    • nmap –mtu [MTU] [target]
  • Use a decoy
    • nmap -D RND: [number] [target]
  • Idle zombie scan
    • nmap -sI [zombie] [target]
  • Manually specify a source port
    • nmap –source-port [port] [target]
  • Append random data
    • nmap –data-length [size] [target]
  • Randomize target scan order
    • nmap –randomize-hosts [target]
  • Spoof MAC Address
    • nmap –spoof-mac [MAC|0|vendor] [target]
  • Send bad checksums
    • nmap –badsum [target]

Output Options

  • Save output to a text file
    • nmap -oN [scan.txt] [target]
  • Save output to a xml file
    • nmap -oX [scan.xml] [target]
  • Grepable output
    • nmap -oG [scan.txt] [target]
  • Output all supported file types
    • nmap -oA [path/filename] [target]
  • Periodically display statistics
    • nmap –stats-every [time] [target]
  • 133t output
    • nmap -oS [scan.txt] [target]

Troubleshooting and debugging

  • Help
    • nmap -h
  • Display Nmap version
    • nmap -V
  • Verbose output
    • nmap -v [target]
  • Debugging
    • nmap -d [target]
  • Display port state reason
    • nmap –reason [target]
  • Only display open ports
    • nmap –open [target]
  • Trace packets
    • nmap –packet-trace [target]
  • Display host networking
    • nmap –iflist
  • Specify a network interface
    • nmap -e [interface] [target]

Nmap Scripting Engine

  • Execute individual scripts
    • nmap –script [script.nse] [target]
  • Execute multiple scripts
    • nmap –script [expression] [target]
  • Script categories
    • all, auth, default, discovery, external, intrusive, malware, safe, vuln
  • Execute scripts by category
    • nmap –script [category] [target]
  • Execute multiple scripts categories
    • nmap –script [category1,category2, etc]
  • Troubleshoot scripts
    • nmap –script [script] –script-trace [target]
  • Update the script database
    • nmap –script-updatedb

Ndiff

  • Comparison using Ndiff
    • ndiff [scan1.xml] [scan2.xml]
  • Ndiff verbose mode
    • ndiff -v [scan1.xml] [scan2.xml]
  • XML output mode
    • ndiff –xml [scan1.xm] [scan2.xml]
Handy Examples:
Nmap Basics:

Scan a single target
	nmap [IP]

Scan multiple IPs
	nmap [IP1,IP2,IP3…]

Scan a list
	nmap -iL [list.txt]

Scan a range of hosts
	nmap [10.1.1.1-10.1.1.200]

Scan an entire subnet
	nmap [IP address/cdir]

Excluding targets from a scan
	nmap [IP] –exclude [IP]

Excluding targets using a list
	nmap [IPs] –excludefile [list.txt]

Create a list of hosts scanned
  	nmap -sL [IPs

     Evasion
Fragment packets
	nmap -f [IP]

Specify a specific MTU
	nmap –mtu [MTU] [IP]

Append random data
	nmap –data-length [size] [IP]

Spoof MAC Address
	nmap –spoof-mac [MAC|0|vendor] [IP]

Send bad checksums
	nmap –badsum [IP]

Output
Save output to a text file
	nmap -oN [scan.txt] [IP]

Save output to a xml file
	nmap -oX [scan.xml] [IP]

Grepable output
	nmap -oG [scan.txt] [IP]

Output all supported file types
	nmap -oA [path/filename] [IP

Comparing Scan Results
Comparison using Ndiff 
	ndiff [scan1.xml] [scan2.xml]

Ndiff verbose mode
	ndiff -v [scan1.xml] [scan2.xml]

XML output mode 
	ndiff –xml [scan1.xm] [scan2.xml]]

Nmap Scripting Engine

Execute individual NSE scripts
	nmap –script [script.nse] [IP]

Execute multiple NSE scripts
	nmap –script [script1.nse,script2.nse…] [IP]

Execute NSE scripts by category
	nmap –script [cat] [target]

Execute multiple NSE script categories
	nmap –script [auth, default…] [IP]

NSE Script categories:
all 
auth
default
discovery
external
intrusive
malware
safe

Nmap default commands:
Usage: nmap [Scan Type(s)] [Options] {target specification}

TARGET SPECIFICATION:
  Can pass hostnames, IP addresses, networks, etc.

  Ex: scanme.nmap.org, microsoft.com/24, 192.168.0.1; 10.0.0-255.1-254
  -iL <inputfilename>: Input from list of hosts/networks
  -iR <num hosts>: Choose random targets
  --exclude <host1[,host2][,host3],...>: Exclude hosts/networks
  --excludefile <exclude_file>: Exclude list from file

HOST DISCOVERY:
  -sL: List Scan - simply list targets to scan
  -sn: Ping Scan - disable port scan
  -Pn: Treat all hosts as online -- skip host discovery
  -PS/PA/PU/PY[portlist]: TCP SYN/ACK, UDP or SCTP discovery to given ports
  -PE/PP/PM: ICMP echo, timestamp, and netmask request discovery probes
  -PO[protocol list]: IP Protocol Ping
  -n/-R: Never do DNS resolution/Always resolve [default: sometimes]
  --dns-servers <serv1[,serv2],...>: Specify custom DNS servers
  --system-dns: Use OS's DNS resolver
  --traceroute: Trace hop path to each host

SCAN TECHNIQUES:
  -sS/sT/sA/sW/sM: TCP SYN/Connect()/ACK/Window/Maimon scans
  -sU: UDP Scan
  -sN/sF/sX: TCP Null, FIN, and Xmas scans
  --scanflags <flags>: Customize TCP scan flags
  -sI <zombie host[:probeport]>: Idle scan
  -sY/sZ: SCTP INIT/COOKIE-ECHO scans
  -sO: IP protocol scan
  -b <FTP relay host>: FTP bounce scan

PORT SPECIFICATION AND SCAN ORDER:
  -p <port ranges>: Only scan specified ports
    Ex: -p22; -p1-65535; -p U:53,111,137,T:21-25,80,139,8080,S:9
  --exclude-ports <port ranges>: Exclude the specified ports from scanning
  -F: Fast mode - Scan fewer ports than the default scan
  -r: Scan ports consecutively - don't randomize
  --top-ports <number>: Scan <number> most common ports
  --port-ratio <ratio>: Scan ports more common than <ratio>

SERVICE/VERSION DETECTION:
  -sV: Probe open ports to determine service/version info
  --version-intensity <level>: Set from 0 (light) to 9 (try all probes)
  --version-light: Limit to most likely probes (intensity 2)
  --version-all: Try every single probe (intensity 9)
  --version-trace: Show detailed version scan activity (for debugging)

SCRIPT SCAN:
  -sC: equivalent to --script=default
  --script=<Lua scripts>: <Lua scripts> is a comma separated list of
           directories, script-files or script-categories
  --script-args=<n1=v1,[n2=v2,...]>: provide arguments to scripts
  --script-args-file=filename: provide NSE script args in a file
  --script-trace: Show all data sent and received
  --script-updatedb: Update the script database.
  --script-help=<Lua scripts>: Show help about scripts.
           <Lua scripts> is a comma-separated list of script-files or
           script-categories.

OS DETECTION:
  -O: Enable OS detection
  --osscan-limit: Limit OS detection to promising targets
  --osscan-guess: Guess OS more aggressively

TIMING AND PERFORMANCE:
  Options which take <time> are in seconds, or append 'ms' (milliseconds),
  's' (seconds), 'm' (minutes), or 'h' (hours) to the value (e.g. 30m).
  -T<0-5>: Set timing template (higher is faster)
  --min-hostgroup/max-hostgroup <size>: Parallel host scan group sizes
  --min-parallelism/max-parallelism <numprobes>: Probe parallelization
  --min-rtt-timeout/max-rtt-timeout/initial-rtt-timeout <time>: Specifies
      probe round trip time.
  --max-retries <tries>: Caps number of port scan probe retransmissions.
  --host-timeout <time>: Give up on target after this long
  --scan-delay/--max-scan-delay <time>: Adjust delay between probes
  --min-rate <number>: Send packets no slower than <number> per second
  --max-rate <number>: Send packets no faster than <number> per second

FIREWALL/IDS EVASION AND SPOOFING:
  -f; --mtu <val>: fragment packets (optionally w/given MTU)
  -D <decoy1,decoy2[,ME],...>: Cloak a scan with decoys
  -S <IP_Address>: Spoof source address
  -e <iface>: Use specified interface
  -g/--source-port <portnum>: Use given port number
  --proxies <url1,[url2],...>: Relay connections through HTTP/SOCKS4 proxies
  --data <hex string>: Append a custom payload to sent packets
  --data-string <string>: Append a custom ASCII string to sent packets
  --data-length <num>: Append random data to sent packets
  --ip-options <options>: Send packets with specified ip options
  --ttl <val>: Set IP time-to-live field
  --spoof-mac <mac address/prefix/vendor name>: Spoof your MAC address
  --badsum: Send packets with a bogus TCP/UDP/SCTP checksum

OUTPUT:
  -oN/-oX/-oS/-oG <file>: Output scan in normal, XML, s|<rIpt kIddi3,
     and Grepable format, respectively, to the given filename.
  -oA <basename>: Output in the three major formats at once
  -v: Increase verbosity level (use -vv or more for greater effect)
  -d: Increase debugging level (use -dd or more for greater effect)
  --reason: Display the reason a port is in a particular state
  --open: Only show open (or possibly open) ports
  --packet-trace: Show all packets sent and received
  --iflist: Print host interfaces and routes (for debugging)
  --log-errors: Log errors/warnings to the normal-format output file
  --append-output: Append to rather than clobber specified output files
  --resume <filename>: Resume an aborted scan
  --stylesheet <path/URL>: XSL stylesheet to transform XML output to HTML
  --webxml: Reference stylesheet from Nmap.Org for more portable XML
  --no-stylesheet: Prevent associating of XSL stylesheet w/XML output

MISC:
  -6: Enable IPv6 scanning
  -A: Enable OS detection, version detection, script scanning, and traceroute
  --datadir <dirname>: Specify custom Nmap data file location
  --send-eth/--send-ip: Send using raw ethernet frames or IP packets
  --privileged: Assume that the user is fully privileged
  --unprivileged: Assume the user lacks raw socket privileges
  -V: Print version number
  -h: Print this help summary page.

EXAMPLES:
  nmap -v -A scanme.nmap.org
  nmap -v -sn 192.168.0.0/16 10.0.0.0/8
  nmap -v -iR 10000 -Pn -p 80
SEE THE MAN PAGE (http://nmap.org/book/man.html) FOR MORE OPTIONS AND EXAMPLES