From Wikipedia, the free encyclopedia

Jump to: navigation, search
Developed by *Hobbit*[1]
Latest release 1.10 / March 20, 1996
Operating system UNIX
Type Network utility
License Permissive free software[2]

netcat is a computer networking utility for reading from and writing to network connections on either TCP or UDP. It goes by the tag-line of "The Swiss-army knife for TCP/IP."

Netcat was voted the second most useful network security tool in a 2000 poll conducted by on the nmap users mailing list.[3] In 2003, it gained fourth place,[4] a position it also held in the 2006 poll.[1]


[edit] Examples

Copy files from machine foo to bar on port 3333 (-l, listen):

 user@bar$ nc -l -p 3333 > backup.iso
 user@foo$ nc bar 3333 < backup.iso 

Open a raw connection to port 25 (like telnet):

 nc 25

Check if UDP ports (-u) 80-90 are open on using zero mode I/O (-z):

 nc -vzu 80-90

Pipe via UDP (-u) with a wait time (-w) of 1 second to 'loggerhost' on port 514

 echo '<0>message' | nc -w 1 -u loggerhost 514

[edit] Variants

The original version of netcat is a UNIX program. Its author is known as *Hobbit*. He released version 1.1 in March 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.

[edit] References

[edit] See also

[edit] External links

Personal tools