#BASH NETCAT PORT CHECK FULL#
#BASH NETCAT PORT CHECK SOFTWARE#
#BASH NETCAT PORT CHECK CODE#
#BASH NETCAT PORT CHECK LICENSE#

To use netcat in this manner, just specify the host options and port needed: # nc 80 The first example presented here is the simplest form of usage of Netcat, as a connection client to other services and websites, avoiding the use of our very old friend, telnet client.

port: TCP/UDP port used for the service.

: IP or name of the host to be connected to.

: Options Parameters and arguments passed to the main command executable, like listen, tcp, etc.

nc: The executable netcat command name, executed on the shell.

Netcat syntax is very easy and simple, and is practically similar in any Unix-like Operating System. There are some implementations of GUIs made by netcat enthusiasts, one of them is GtkNetCat with a very user-friendly and intuitive interface. Netcat doesn’t have an official GUI (Graphical User Interface) due to the fact that its use generally made all on the command line. Netcat was developed to be easily used with very intuitive command-line arguments.

#BASH NETCAT PORT CHECK CODE#

For the purists, Netcat can also be download in source code to be compiled in other more specific systems.

#BASH NETCAT PORT CHECK SOFTWARE#

Nowadays, due to it’s great importance for network administrators and security specialists, mainly security penetration testing specialists, Netcat is available in the most unix-like software repositories, what avoids the time consuming procedure of installing it by hand through compilation.

#BASH NETCAT PORT CHECK LICENSE#

The best of it all, netcat is totally free, distributed under the GNU General Public License (GPL), can be downloaded for Linux, FreeBSD, NetBSD, SunOS/Solaris, MacOS X, Windows, among other systems, directly from it’s official website ().

Optional functions of telnet protocol reply.

Ability to read command-line arguments from the standard input (stdin).Ability to use any locally configured network IP address.Ability to work in any local TCP/IP port.

#BASH NETCAT PORT CHECK FULL#

Full DNS checks (forward / reverse) with warning messages.

Intput/Output Connections, TCP or UDP, with origin or destination in any TCP/IP stack protocol port.

Yet, netcat can be easily used for a series of maintenance, development information gathering and network troubleshooting tasks because it simulates nearly every existing network connection type, among other things like: Netcat can be integrated with other software and scripts for a series of network tasks which utility and approach depend solely on the user’s imagination and TCP/IP knowledge. It was developed to be a reliable back-end tool that can be used directly on the system command line, or indirectly by scripts. Netcat, developed in 2004 by a developer known as Hobbit, is a simple, but very handy, network tool to read and write data across networks using the TCP/IP stack protocols, and can be used to create the most different services, for connectivity tests and security purposes. The problem here is that, besides taking a long time to perform, sometimes the service take a lot of time and complexity to be configured just for a simple test, and at this step, we simply need an easy way to test our networks and services. The standard way to perform such a procedure is to get some network services up in the right servers and simply test them. This article was initially published in Portuguese therefore I’ve translated it into English.Īs security or infrastructure specialists, we constantly need to test our networks, which can be very time-consuming, just to validate simple firewall rules and connectivity between the networks. Here below is an article I have written and published in a very well-known Brazilian IT magazine called Infra Magazine, more specifically on issue number 3. Netcat is a very good piece of software used all around the world by security and IT professionals, in general, to accomplish many different goals, from loading a simple socket in a specific port to test network connectivity, to develop full backdoors for other meanings.

Bash netcat port check