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NeSSi2 2.1.2 has been released

Available for download now!


NeSSi2 2.1.1 has been released

Available for download now!


Error with Win32 UI zip file

The zip-file for the Win32 version was damaged, after decompressing it showed duplicate files. We...


See NeSSi2 in action: Lange Nachte der Wissenschaften 2012 (Science Night 2012)

June 2, from 17-01


Network Security Simulator


Developed by

Logo DAI-Labor

Logo Telekom Laboratories

Hosted at

Get NeSSi2 at Fast, secure and Free Open Source software downloads

Welcome to the home of NeSSi² - the Network Security Simulator.

NeSSi² is an open source project developed at the DAI-Labor and sponsored by Deutsche Telekom Laboratories.

NeSSi (Network Security Simulator) is a novel network simulation tool which incorporates a variety of features relevant to network security distinguishing it from general-purpose network simulators. Its capabilities such as profile-based automated attack generation, traffic analysis and support for the detection algorithm plugins allow it to be used for security research and evaluation purposes.

NeSSi has been successfully used for testing intrusion detectionalgorithms, conducting network security analysis, and developingoverlay security frameworks (see Publications).

NeSSi² is built upon the agent framework JIAC, resulting in a distributed and easy-to-extend architecture.

For more information on the NeSSi² license, how to contribute to NeSSi² or how to use the downloaded software please contact us at


Join the Development Team

Visit our NeSSi² development site on Sourceforge and help us to improve and extend NeSSi².