Dynamips is a Cisco router emulator written by Christophe Fillot. It emulates 1700, 2600, 3600, 3700, and 7200 hardware platforms, and runs standard IOS images. In Chris’ own words:

This kind of emulator would be useful to:

· Be used as a training platform, with software used in real world. It would allow people to become more familiar with Cisco devices, Cisco being the world leader in networking technologies ;

· Test and experiment features of Cisco IOS ;

· Check quickly configurations to be deployed later on real routers.

Dynagen software can be downloaded as follows:

http://sourceforge.net/project/showfiles.php?group_id=160317&package_id=192619

In addition, you can get started quickly with using this software by the following tutorial:

http://dynagen.org/tutorial.htm

Note: you must have winpcap on your computer to run dynagen. You can download it as follows:

http://www.winpcap.org/install/default.htm

For more information, feel free to post your queries.

(reference:http://dynagen.org/)