GNS3 is a graphical network simulator that allows simulation of complex networks.
To allow complete simulations, GNS3 is strongly linked with :
- Dynamips, the core program that allows Cisco IOS emulation.
- Dynagen, a text-based front-end for Dynamips.
- Qemu, a generic and open source machine emulator and virtualizer.
GNS3 is an excellent complementary tool to real labs for network engineers, administrators and people wanting to pass certifications such as CCNA, CCNP, CCIP, CCIE, JNCIA, JNCIS, 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.
This project is an open source, free program that may be used on multiple operating systems, including Windows, Linux, and MacOS X.
- Design of high quality and complex network topologies.
- Emulation of many Cisco IOS router platforms, IPS, PIX and ASA firewalls, JunOS.
- Simulation of simple Ethernet, ATM and Frame Relay switches.
- Connection of the simulated network to the real world!
- Packet capture using Wireshark.
Important notice: users have to provide their own IOS/IPS/PIX/ASA/JunOS to use with GNS3.
You can download GNS3 v0.7.2 here:
A tutorial for GNS3 0.5 is available here (highly recommended for beginners).
Also check this quick start guide to GNS3 and VMware by Yogesh.
GNS3 has been developed in python and through PyQt the GUI part is made with the powerful Qt library , famous for its use in the KDE project. GNS3 uses the SVG technology (Scalable Vector Graphics) to provide high quality symbols for designing your network topologies.
- Internet LAB Tutorial Part 2
- Installation Tutorial for Linux
- How to build an Internet Lab
- GNS3 Graphical router emulation software
- Switching lab Part 2 (router on a stick)
- How to build a switching lab Part 1
- How to install and enable ASDM (PIX firewall) using GNS3
- How to configure IOS IPS (Intrusion Prevention System) using SDM in GNS3
- How to use Pemu as your personal firewall
- How to communicate with Pemu
- Pemu PIX emulator with GNS3
- How to build a voice lab with GNS3 and VMWare
- How to use a third party SIP phone with Cisco routers using GNS3
- How to setup Call Manager Express (CME) router using GNS3
- How to configure Cisco Unified Call Manager Express GUI using GNS3
- How to configure Cisco Unified Call Manager Express (CUCME) router for XML Services
- How to register third party SIP phone to Cisco Unified Call Manager Express (CUCME)
- How to setup CME SIP trunk to VoIP SIP Service Provider Part 1
- Qemu 0.11.0 patching and compilation
- Installation of FreeBSD 4.11
- JunOS 8.5R1.14 installation
- GNS3 configuration part 1
- GNS3 configuration part 2
- JunOS upgrade from 8.5R1.14 to 9.6R1.13
- Jweb 9.6R1.13 installation
- Connecting JunOS Olive to the real world
- How to save labs with router configs
- How to build a frame-relay lab
- How to integrate a Microsoft Loopback interface with GNS3
- How to use Putty for console access
- How to use Putty Connection Manager for console access
- How to setup and install Cisco Security Device Manager (SDM) on router using GNS3
- How to setup and configure Cisco Configuration Professional (CCP)
- How to lockdown Cisco Router’s Configuration Access
- How to configure and setup IPv6 connectivity between Windows XP and Cisco Router
- How to run multi-pc topology using distributed hypervisors in GNS3