Nmap Cheat Sheet
Basic Scanning Techniques
- Scan a single target
- Scan multiple targets
-
nmap [target1,target2,etc]
- Scan a list of targets
- Scan a range of hosts
- `nmap [range of IP addresses]
- Scan an entire subnet
- Scan random hosts
- Excluding targets from a scan
-
nmap [targets] –exclude [targets]
- Excluding targets using a list
-
nmap [targets] –excludefile [list.txt]
- Perform an aggressive scan
- Scan an IPv6 target
Discovery Options
- Perform a ping scan only
- Don’t ping
- TCP SYN Ping
- TCP ACK ping
- UDP ping
- SCTP Init Ping
- ICMP echo ping
- ICMP Timestamp ping
- ICMP address mask ping
- IP protocol ping
- ARP ping
- Traceroute
-
nmap –traceroute [target]
- Force reverse DNS resolution
- Disable reverse DNS resolution
- Alternative DNS lookup
-
nmap –system-dns [target]
- Manually specify DNS servers
-
nmap –dns-servers [servers] [target]
- Create a host list
Advanced Scanning Options
- TCP SYN Scan
- TCP connect scan
- UDP scan
- TCP Null scan
- TCP Fin scan
- Xmas scan
- TCP ACK scan
- Custom TCP scan
-
nmap –scanflags [flags] [target]
- IP protocol scan
- Send Raw Ethernet packets
- Send IP packets
Port Scanning Options
- Perform a fast scan
- Scan specific ports
- 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
- Scan top ports
- `nmap –top-ports [number] [target]
- Perform a sequential port scan
Version Detection
- Operating system detection
- Submit TCP/IP Fingerprints
-
http://www.nmap.org/submit/
- Attempt to guess an unknown
-
nmap -O –osscan-guess [target]
- Service version detection
- Troubleshooting version scans
-
nmap -sV –version-trace [target]
- Perform a RPC scan
Timing Options
- Timing Templates
- 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
- Specify a specific MTU
- 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
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
- Display Nmap version
- Verbose output
- Debugging
- Display port state reason
- Only display open ports
- Trace packets
-
nmap –packet-trace [target]
- Display host networking
- 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
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]
Links
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