Netcat Explained

netcat is a computer networking utility for reading from and writing to network connections on either TCP or UDP.

Netcat was voted the second most useful network security tool in a 2000 poll conducted by insecure.org on the nmap users mailing list.^[1] In 2003, it gained fourth place,^[2] a position it also held in the 2006 poll.^[3]

Variants

The original version of netcat is a UNIX program. Its author is known as

• Hobbit*

. He released version 1.1 in March of 1996.

Netcat is fully POSIX compatible and there exist several implementations, including a rewrite from scratch known as GNU netcat, which is maintained by Giovanni Giacobbi and an MS-Windows version of netcat created by Chris Wysopal. Andreas Bischoff has ported the Windows version to Windows CE (now known as Windows Mobile).

On some systems, modified versions or similar utilities go by the command name(s) nc, ncat, pnetcat, socat, sock, socket, sbd.

socat is a more complex cousin of netcat. It is larger and more flexible than netcat, and has more options that must be configured for a given task.

Cryptcat is a version of netcat with integrated transport encryption capabilities.

See also

• TELNET
• List of Unix programs

External links

• OpenBSD nc(1) man page via OpenBSD
• GNU netcat
• Netcat for Windows
• Socat
• Netcat for Windows CE (PocketPC, Windows Mobile)

Notes and References

1. Web site: Top 50 Security Tools. 2000. 2007-09-30.
2. Web site: Top 75 Security Tools. 2003. 2007-09-30.
3. Web site: Top 100 Security Tools. 2006. 2008-02-18.