Want to have a good start with GNS3? Please watch this absolutely excellent video: GNS3 overview and operation by Jeremy Cioara from CBT Nuggets (37 minutes).
Then read our official tutorials:
- Introduction to GNS3
- GNS3 Quick Start Guide for Windows Users
- GNS3 Quick Start Guide for Linux Users
- Creating the simplest topology
- Building more complex topologies
- Uncompressing Cisco IOS images
- Using terminal programs with GNS3
- Connecting GNS3 to real networks
- Memory and CPU usage
- Packet Capture using Wireshark
- Connecting hosts to your Topologies
- Switching simulation in GNS3
- Client-Server and Multi-Server mode
- Cisco PIX Firewall emulation
- VirtualBox emulation
Remember, even if GNS3 is about simulation, it actually emulates most of the devices in order to provide an accurate simulation. Please see the complete list of hardware emulated by GNS3
Finally, as complementary help, do not hesitate to watch these video tutorials showing GNS3 simulating Cisco and Juniper topologies. Some of them are really helpful if you are studying for certification tracks like security or voice (CCNP or CCIE).
Users who are looking for help or want to report bugs can post on our forum.
An IRC channel is also available on Freenode dedicated servers, named #gns3. You can connect using an IRC client, if you don’t have one, please use this web client. This channel is to talk about anything concerning GNS3: future releases, new features, ideas etc.
You can contribute by reporting bugs (on the forum, development section), creating tutorials or giving suggestions.
We are also looking for people who can translate GNS3 into their own language. A translation how to is available to help you.