You can send data to a specific port without needing NetCat by using the /dev/tcp or /dev/udp special files in Linux, depending on whether you want to use TCP or UDP for the connection.

Sending Data

The /dev/udp and /dev/tcp special files allow you to send data to a specific port on a local or remote machine. Here is the syntax for sending data using these special files:

echo "Hello World" > /dev/[udp|tcp]/<host>/<port>

Here are some example of sending the string “Hello World” to a local port 8888:

# Sending data using UDP
echo "Hello World" > /dev/udp/127.0.0.1/8888

# Sending data using TCP
echo "Hello World" > /dev/tcp/127.0.0.1/8888

Explanation:

  • /dev/udp/ or /dev/tcp/: These special files allow you to send data to a specific port using either UDP or TCP.
  • <host>: The IP address or hostname of the target machine.
  • <port>: The port number on the target machine.
  • echo "Hello World": The message you want to transmit. This can be any string or data you want to send. (Ex. cat file.txt > /dev/udp/127.0.0.1/8888)

This is a super useful method for quickly testing connectivity without needing to install additional tools like NetCat. Happy testing! 🙂