Network Security

Netcat – networking utility

Netcat is a networking utility which reads and writes data across network connections, using the TCP/IP protocol.

It is designed to be a reliable “back-end” tool that can be used directly or easily driven by other programs and scripts.

At the same time, it is a feature-rich network debugging and exploration tool, since it can create almost any kind of connection you would need and has several interesting built-in capabilities.

Netcat is a rewrite of the original netcat with support for IPv6 and an enhanced support for UDP.

Netcat has three main modes of functionality. These are the connect mode, the listen mode, and the tunnel mode.

The most common mode is the connect mode, which for example allows the output of a locally called command to be redirected for example to a remote netcat listening or to any other kind of daemon waiting for a connection.

On the other hand, the listen mode can be used to obtain some kind of stream of data from a remote site.

The most new feature is the tunnel mode, which is a powerful and reliable mode that allows tunneling a remote site towards any other remote site, allowing to specify for example from which interface create the connection and from which port.

Key Features

  • Outbound and inbound connections, TCP or UDP, to or from any ports.
  • Featured tunneling mode which allows also special tunneling such as UDP to TCP, with the possibility of specifying all network parameters (source port/interface, listening port/interface, and the remote host allowed to connect to the tunnel.
  • Built-in port-scanning capabilities, with randomizer.
  • Advanced usage options, such as buffered send-mode (one line every N seconds), and hexdump (to stderr or to a specified file) of transmitted and received data.
  • Optional RFC854 telnet codes parser and responder.

Website: netcat.sourceforge.net
Support:
Developer: Gabriele Giorgetti
License: GNU General Public License v2.0

Netcat is written in C. Learn C with our recommended free books and free tutorials.


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havnFast configurable port scanner
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turbo-scannerPort scanner and service detection tool

Read our verdict in the software roundup.


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