This is the traditional method that made GNS3 famous.
Where to get Cisco IOS files for GNS3. - Spiceworks Community ios gns3 images download
Generally, no. Cisco does not offer free iOS binaries. However, Cisco DevNet Sandbox provides temporary access to IOSv devices in the cloud for free. This is the traditional method that made GNS3 famous
When you finally acquire your images, you will notice different file extensions and simulation methods. GNS3 supports several ways to run Cisco software: ios gns3 images download
If you have a modern PC with 16GB+ RAM and a CPU that supports virtualization (VT-x/AMD-V