Paul Samsotha psamsotha

Often referred to as the "swiss army of knife" for TCP/IP networking, [Netcat][1] is an extremely versatile Linux utility that allows you to do anything under the sun using TCP/UDP sockets. It is one of the most favorite tools for system admins when they need to do networking related troubleshooting and experimentation.

In this tutorial, I am sharing a few useful netcat examples, although the sky is the limit when it comes to possible netcat use cases. If you are using netcat regularly, feel free to share your use case.

Note that when you are binding to well-known ports (0-1023) with nc, you need root privilege. Otherwise, run nc as a normal user.

1. Test if a particular TCP port of a remote host is open.

$ nc -vn 192.168.233.208 5000

	# define base image as python slim-buster.
	FROM python:3.7-slim-buster as base

	## start builder stage.

	# this is the first stage of the build.
	# it will install all requirements.
	FROM base as builder

	# install all packages for chromedriver: https://gist.github.com/varyonic/dea40abcf3dd891d204ef235c6e8dd79