Graphical Network Simulator
What is GNS3?
GNS3 is a graphical network simulator that allows simulation of complex networks.
To provide complete and accurate simulations, GNS3 is strongly linked with: * Dynamips, a Cisco IOS emulator. * Dynagen, a text-based front end for Dynamips. * Qemu, a generic and open source machine emulator and virtualizer. * VirtualBox, a free and powerful virtualization software.
GNS3 is an excellent complementary tool to real labs for network engineers, administrators and people wanting to study for certifications such as Cisco CCNA, CCNP, CCIP and CCIE as well as Juniper JNCIA, JNCIS and JNCIE.
It can also be used to experiment features of Cisco IOS, Juniper JunOS or to check configurations that need to be deployed later on real routers.
Thanks to VirtualBox integration, now even system engineers and administrators can take advantage of GNS3 to make labs and study for Redhat (RHCE, RHCT), Microsoft (MSCE, MSCA), Novell (CLP) and many other vendor certifications.
This project is an open source, free program that may be used on multiple operating systems, including Windows, Linux, and MacOS X.
Introduction to GNS3:
GNS3 is a Graphical Network Simulator that allows emulation of complex networks. You may be familiar with VMWare, VirtualBox or Virtual PC that are used to emulate various operating systems in a virtual environment. These programs allow you to run operating systems such as Windows XP Professional or Ubuntu Linux in a virtual environment on your computer. GNS3 allows the same type of emulation using Cisco Internetwork Operating Systems. It allows you to run a Cisco IOS in a virtual environment on your computer. Dynamips is the core program that allows IOS emulation. GNS3 runs on top of Dynamips to create a more user friendly, graphical environment.
GNS3 also supports other emulation programs, namely Qemu, Pemu and VirtualBox. These softwares are used to emulate Cisco ASA and PIX firewalls, Cisco