NetCat

NetCat (nc) is used to read and write to TCP and UDP network connections. It is an excellent tool for diagnosing network connectivity issues.

Installation

sudo apt-get install netcat

Usage

To listen to a specific port.

nc -l -p 8000

To write to a specific port

nc 127.0.0.1 8000
nc -v 127.0.0.1 8000