Nmap: a free, open-source security tool for network exploration and auditing; identifies hosts, open ports, services, OS, and potential vulnerabilities.
Nmap, short for Network Mapper, is a free and open-source security tool used for network exploration, management, and security auditing. It is designed to provide users with a comprehensive and accurate view of a network's structure, devices, and services. Nmap uses a variety of techniques to identify active hosts, operating systems, open ports, and running services.
One of the primary features of Nmap is its ability to conduct "port scanning," which is the process of scanning a host or network for open ports. This is done by sending packets to various ports on the target machine, and analyzing the responses received. The information gathered from port scanning can be used to determine which services are running on the target machine, and identify potential vulnerabilities that could be exploited by an attacker.
Nmap also has the ability to detect the operating system (OS) of a target machine. This is done by analyzing the responses received from the machine during the port scanning process. Nmap uses various techniques to identify the OS, such as analyzing the TTL values of packets received, examining the responses to TCP/IP fingerprinting, and analyzing the behavior of the target machine during the scanning process.
Another feature of Nmap is its ability to perform "service enumeration," which is the process of identifying the services that are running on a target machine. This is done by analyzing the responses received from the machine during the port scanning process. Nmap can identify a wide variety of services, including HTTP, SMTP, FTP, DNS, SSH, and more.
In addition to these features, Nmap also includes a variety of other tools and features that make it a valuable security tool. For example, it includes the ability to perform "traceroute" functionality, which can be used to determine the path that packets take between two hosts. It also includes the ability to perform "ping scanning," which is the process of sending ICMP packets to a target machine to determine if it is active.
Nmap can be used by both security professionals and system administrators to identify potential vulnerabilities and security risks in their network. It can also be used by attackers to identify potential targets and vulnerabilities in a network. However, it should be noted that using Nmap for malicious purposes is illegal and can result in severe legal consequences.
Overall, Nmap is a powerful and versatile security tool that can be used to provide valuable information about a network's structure and security posture. Its ease of use, comprehensive feature set, and open-source nature make it a popular choice among security professionals and enthusiasts alike.
nmap Usage Example
Scan in verbose mode (-v), enable OS detection, version detection, script scanning, and traceroute (-A), with version detection (-sV) against the target IP (192.168.1.1):
:~# nmap -v -A -sV 192.168.1.1
Starting Nmap 6.45 ( http://nmap.org ) at 2014-05-13 18:40 MDT
NSE: Loaded 118 scripts for scanning.
NSE: Script Pre-scanning.
Initiating ARP Ping Scan at 18:40
Scanning 192.168.1.1 [1 port]
Completed ARP Ping Scan at 18:40, 0.06s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 18:40
Completed Parallel DNS resolution of 1 host. at 18:40, 0.00s elapsed
Initiating SYN Stealth Scan at 18:40
Scanning router.localdomain (192.168.1.1) [1000 ports]
Discovered open port 53/tcp on 192.168.1.1
Discovered open port 22/tcp on 192.168.1.1
Discovered open port 80/tcp on 192.168.1.1
Discovered open port 3001/tcp on 192.168.1.1
nping Usage Example
Using TCP mode (–tcp) to probe port 22 (-p 22) using the SYN flag (–flags syn) with a TTL of 2 (–ttl 2) on the remote host (192.168.1.1):
:~# nping --tcp -p 22 --flags syn --ttl 2 192.168.1.1
Starting Nping 0.6.45 ( http://nmap.org/nping ) at 2014-05-13 18:43 MDT
SENT (0.0673s) TCP 192.168.1.15:60125 > 192.168.1.1:22 S ttl=2 id=54240 iplen=40 seq=1720523417 win=1480
RCVD (0.0677s) TCP 192.168.1.1:22 > 192.168.1.15:60125 SA ttl=64 id=0 iplen=44 seq=3377886789 win=5840 <mss 1460>
SENT (1.0678s) TCP 192.168.1.15:60125 > 192.168.1.1:22 S ttl=2 id=54240 iplen=40 seq=1720523417 win=1480
RCVD (1.0682s) TCP 192.168.1.1:22 > 192.168.1.15:60125 SA ttl=64 id=0 iplen=44 seq=3393519366 win=5840 <mss 1460>
SENT (2.0693s) TCP 192.168.1.15:60125 > 192.168.1.1:22 S ttl=2 id=54240 iplen=40 seq=1720523417 win=1480
RCVD (2.0696s) TCP 192.168.1.1:22 > 192.168.1.15:60125 SA ttl=64 id=0 iplen=44 seq=3409166569 win=5840 <mss 1460>
SENT (3.0707s) TCP 192.168.1.15:60125 > 192.168.1.1:22 S ttl=2 id=54240 iplen=40 seq=1720523417 win=1480
RCVD (3.0710s) TCP 192.168.1.1:22 > 192.168.1.15:60125 SA ttl=64 id=0 iplen=44 seq=3424813300 win=5840 <mss 1460>
SENT (4.0721s) TCP 192.168.1.15:60125 > 192.168.1.1:22 S ttl=2 id=54240 iplen=40 seq=1720523417 win=1480
RCVD (4.0724s) TCP 192.168.1.1:22 > 192.168.1.15:60125 SA ttl=64 id=0 iplen=44 seq=3440460772 win=5840 <mss 1460>
Max rtt: 0.337ms | Min rtt: 0.282ms | Avg rtt: 0.296ms
Raw packets sent: 5 (200B) | Rcvd: 5 (230B) | Lost: 0 (0.00%)
Nping done: 1 IP address pinged in 4.13 seconds
ndiff Usage Example
Compare yesterday’s port scan (yesterday.xml) with the scan from today (today.xml):
:~# ndiff yesterday.xml today.xml
-Nmap 6.45 scan initiated Tue May 13 18:46:43 2014 as: nmap -v -F -oX yesterday.xml 192.168.1.1
+Nmap 6.45 scan initiated Tue May 13 18:47:58 2014 as: nmap -v -F -oX today.xml 192.168.1.1
endian.localdomain (192.168.1.1, 00:01:6C:6F:DD:D1):
-Not shown: 96 filtered ports
+Not shown: 97 filtered ports
PORT STATE SERVICE VERSION
-22/tcp open ssh
ncat Usage Example
Be verbose (-v), running /bin/bash on connect (–exec “/bin/bash”), only allowing 1 IP address (–allow 192.168.1.123), listen on TCP port 4444 (-l 4444), and keep the listener open on disconnect (–keep-open):
:~# ncat -v --exec "/bin/bash" --allow 192.168.1.123 -l 4444 --keep-open
Ncat: Version 6.45 ( http://nmap.org/ncat )
Ncat: Listening on :::4444
Ncat: Listening on 0.0.0.0:4444
Ncat: Connection from 192.168.1.123.
Ncat: Connection from 192.168.1.123:39501.
Ncat: Connection from 192.168.1.15.
Ncat: Connection from 192.168.1.15:60393.
Ncat: New connection denied: not allowed
Packages and Binaries:
ncat
ncat is a reimplementation of Netcat by the NMAP project, providing most of the features present in the original implementations, along with some new features such as IPv6 and SSL support. Port scanning support has been removed.
Installed size:820 KBHow to install:sudo apt install ncat
Dependencies:
libc6
liblua5.3-0
libssl3
ncat
Concatenate and redirect sockets
:~# ncat -h
Ncat 7.93 ( https://nmap.org/ncat )
Usage: ncat [options] [hostname] [port]
Options taking a time assume seconds. Append 'ms' for milliseconds,
's' for seconds, 'm' for minutes, or 'h' for hours (e.g. 500ms).
-4 Use IPv4 only
-6 Use IPv6 only
-U, --unixsock Use Unix domain sockets only
--vsock Use vsock sockets only
-C, --crlf Use CRLF for EOL sequence
-c, --sh-exec <command> Executes the given command via /bin/sh
-e, --exec <command> Executes the given command
--lua-exec <filename> Executes the given Lua script
-g hop1[,hop2,...] Loose source routing hop points (8 max)
-G <n> Loose source routing hop pointer (4, 8, 12, ...)
-m, --max-conns <n> Maximum <n> simultaneous connections
-h, --help Display this help screen
-d, --delay <time> Wait between read/writes
-o, --output <filename> Dump session data to a file
-x, --hex-dump <filename> Dump session data as hex to a file
-i, --idle-timeout <time> Idle read/write timeout
-p, --source-port port Specify source port to use
-s, --source addr Specify source address to use (doesn't affect -l)
-l, --listen Bind and listen for incoming connections
-k, --keep-open Accept multiple connections in listen mode
-n, --nodns Do not resolve hostnames via DNS
-t, --telnet Answer Telnet negotiations
-u, --udp Use UDP instead of default TCP
--sctp Use SCTP instead of default TCP
-v, --verbose Set verbosity level (can be used several times)
-w, --wait <time> Connect timeout
-z Zero-I/O mode, report connection status only
--append-output Append rather than clobber specified output files
--send-only Only send data, ignoring received; quit on EOF
--recv-only Only receive data, never send anything
--no-shutdown Continue half-duplex when receiving EOF on stdin
--allow Allow only given hosts to connect to Ncat
--allowfile A file of hosts allowed to connect to Ncat
--deny Deny given hosts from connecting to Ncat
--denyfile A file of hosts denied from connecting to Ncat
--broker Enable Ncat's connection brokering mode
--chat Start a simple Ncat chat server
--proxy <addr[:port]> Specify address of host to proxy through
--proxy-type <type> Specify proxy type ("http", "socks4", "socks5")
--proxy-auth <auth> Authenticate with HTTP or SOCKS proxy server
--proxy-dns <type> Specify where to resolve proxy destination
--ssl Connect or listen with SSL
--ssl-cert Specify SSL certificate file (PEM) for listening
--ssl-key Specify SSL private key (PEM) for listening
--ssl-verify Verify trust and domain name of certificates
--ssl-trustfile PEM file containing trusted SSL certificates
--ssl-ciphers Cipherlist containing SSL ciphers to use
--ssl-servername Request distinct server name (SNI)
--ssl-alpn ALPN protocol list to use
--version Display Ncat's version information and exit
See the ncat(1) manpage for full options, descriptions and usage examples
ndiff
Ndiff is a tool to aid in the comparison of Nmap scans. It takes two Nmap XML output files and prints the differences between them them: hosts coming up and down, ports becoming open or closed, and things like that. It can produce output in human-readable text or machine-readable XML formats.
Installed size:423 KBHow to install:sudo apt install ndiff
Dependencies:
python3
python3-lxml
ndiff
Utility to compare the results of Nmap scans
:~# ndiff -h
Usage: /usr/bin/ndiff [option] FILE1 FILE2
Compare two Nmap XML files and display a list of their differences.
Differences include host state changes, port state changes, and changes to
service and OS detection.
-h, --help display this help
-v, --verbose also show hosts and ports that haven't changed.
--text display output in text format (default)
--xml display output in XML format
nmap
Nmap is a utility for network exploration or security auditing. It supports ping scanning (determine which hosts are up), many port scanning techniques, version detection (determine service protocols and application versions listening behind ports), and TCP/IP fingerprinting (remote host OS or device identification). Nmap also offers flexible target and port specification, decoy/stealth scanning, sunRPC scanning, and more. Most Unix and Windows platforms are supported in both GUI and commandline modes. Several popular handheld devices are also supported, including the Sharp Zaurus and the iPAQ.
Installed size:4.85 MBHow to install:sudo apt install nmap
Dependencies:
libc6
libgcc-s1
liblinear4
liblua5.3-0
libpcre3
libssh2-1
libssl3
libstdc++6
lua-lpeg
nmap-common
zlib1g
nmap
Network exploration tool and security / port scanner
:~# nmap -h
Nmap 7.93 ( https://nmap.org )
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 sequentially - 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)
--append-output: Append to rather than clobber specified output files
--resume <filename>: Resume an aborted scan
--noninteractive: Disable runtime interactions via keyboard
--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 (https://nmap.org/book/man.html) FOR MORE OPTIONS AND EXAMPLES
nping
Network packet generation tool / ping utility
:~# nping -h
Nping 0.7.93 ( https://nmap.org/nping )
Usage: nping [Probe mode] [Options] {target specification}
TARGET SPECIFICATION:
Targets may be specified as hostnames, IP addresses, networks, etc.
Ex: scanme.nmap.org, microsoft.com/24, 192.168.0.1; 10.0.*.1-24
PROBE MODES:
--tcp-connect : Unprivileged TCP connect probe mode.
--tcp : TCP probe mode.
--udp : UDP probe mode.
--icmp : ICMP probe mode.
--arp : ARP/RARP probe mode.
--tr, --traceroute : Traceroute mode (can only be used with
TCP/UDP/ICMP modes).
TCP CONNECT MODE:
-p, --dest-port <port spec> : Set destination port(s).
-g, --source-port <portnumber> : Try to use a custom source port.
TCP PROBE MODE:
-g, --source-port <portnumber> : Set source port.
-p, --dest-port <port spec> : Set destination port(s).
--seq <seqnumber> : Set sequence number.
--flags <flag list> : Set TCP flags (ACK,PSH,RST,SYN,FIN...)
--ack <acknumber> : Set ACK number.
--win <size> : Set window size.
--badsum : Use a random invalid checksum.
UDP PROBE MODE:
-g, --source-port <portnumber> : Set source port.
-p, --dest-port <port spec> : Set destination port(s).
--badsum : Use a random invalid checksum.
ICMP PROBE MODE:
--icmp-type <type> : ICMP type.
--icmp-code <code> : ICMP code.
--icmp-id <id> : Set identifier.
--icmp-seq <n> : Set sequence number.
--icmp-redirect-addr <addr> : Set redirect address.
--icmp-param-pointer <pnt> : Set parameter problem pointer.
--icmp-advert-lifetime <time> : Set router advertisement lifetime.
--icmp-advert-entry <IP,pref> : Add router advertisement entry.
--icmp-orig-time <timestamp> : Set originate timestamp.
--icmp-recv-time <timestamp> : Set receive timestamp.
--icmp-trans-time <timestamp> : Set transmit timestamp.
ARP/RARP PROBE MODE:
--arp-type <type> : Type: ARP, ARP-reply, RARP, RARP-reply.
--arp-sender-mac <mac> : Set sender MAC address.
--arp-sender-ip <addr> : Set sender IP address.
--arp-target-mac <mac> : Set target MAC address.
--arp-target-ip <addr> : Set target IP address.
IPv4 OPTIONS:
-S, --source-ip : Set source IP address.
--dest-ip <addr> : Set destination IP address (used as an
alternative to {target specification} ).
--tos <tos> : Set type of service field (8bits).
--id <id> : Set identification field (16 bits).
--df : Set Don't Fragment flag.
--mf : Set More Fragments flag.
--evil : Set Reserved / Evil flag.
--ttl <hops> : Set time to live [0-255].
--badsum-ip : Use a random invalid checksum.
--ip-options <S|R [route]|L [route]|T|U ...> : Set IP options
--ip-options <hex string> : Set IP options
--mtu <size> : Set MTU. Packets get fragmented if MTU is
small enough.
IPv6 OPTIONS:
-6, --IPv6 : Use IP version 6.
--dest-ip : Set destination IP address (used as an
alternative to {target specification}).
--hop-limit : Set hop limit (same as IPv4 TTL).
--traffic-class <class> : : Set traffic class.
--flow <label> : Set flow label.
ETHERNET OPTIONS:
--dest-mac <mac> : Set destination mac address. (Disables
ARP resolution)
--source-mac <mac> : Set source MAC address.
--ether-type <type> : Set EtherType value.
PAYLOAD OPTIONS:
--data <hex string> : Include a custom payload.
--data-string <text> : Include a custom ASCII text.
--data-length <len> : Include len random bytes as payload.
ECHO CLIENT/SERVER:
--echo-client <passphrase> : Run Nping in client mode.
--echo-server <passphrase> : Run Nping in server mode.
--echo-port <port> : Use custom <port> to listen or connect.
--no-crypto : Disable encryption and authentication.
--once : Stop the server after one connection.
--safe-payloads : Erase application data in echoed packets.
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, 0.25h).
--delay <time> : Adjust delay between probes.
--rate <rate> : Send num packets per second.
MISC:
-h, --help : Display help information.
-V, --version : Display current version number.
-c, --count <n> : Stop after <n> rounds.
-e, --interface <name> : Use supplied network interface.
-H, --hide-sent : Do not display sent packets.
-N, --no-capture : Do not try to capture replies.
--privileged : Assume user is fully privileged.
--unprivileged : Assume user lacks raw socket privileges.
--send-eth : Send packets at the raw Ethernet layer.
--send-ip : Send packets using raw IP sockets.
--bpf-filter <filter spec> : Specify custom BPF filter.
OUTPUT:
-v : Increment verbosity level by one.
-v[level] : Set verbosity level. E.g: -v4
-d : Increment debugging level by one.
-d[level] : Set debugging level. E.g: -d3
-q : Decrease verbosity level by one.
-q[N] : Decrease verbosity level N times
--quiet : Set verbosity and debug level to minimum.
--debug : Set verbosity and debug to the max level.
EXAMPLES:
nping scanme.nmap.org
nping --tcp -p 80 --flags rst --ttl 2 192.168.1.1
nping --icmp --icmp-type time --delay 500ms 192.168.254.254
nping --echo-server "public" -e wlan0 -vvv
nping --echo-client "public" echo.nmap.org --tcp -p1-1024 --flags ack
SEE THE MAN PAGE FOR MANY MORE OPTIONS, DESCRIPTIONS, AND EXAMPLES
nmap-common
Nmap is a utility for network exploration or security auditing. It supports ping scanning (determine which hosts are up), many port scanning techniques, version detection (determine service protocols and application versions listening behind ports), and TCP/IP fingerprinting (remote host OS or device identification). Nmap also offers flexible target and port specification, decoy/stealth scanning, sunRPC scanning, and more. Most Unix and Windows platforms are supported in both GUI and commandline modes. Several popular handheld devices are also supported, including the Sharp Zaurus and the iPAQ.
This package contains the nmap files shared by all architectures.
Installed size:20.74 MBHow to install:sudo apt install nmap-common
