To legally download Cisco switch images for GNS3, you have two primary options: CiscoIOS Images for GNS3 - Cisco Community
If you are a network engineer, a CCNP or CCIE candidate, or a curious student, you have likely faced a frustrating reality: While GNS3 excels at emulating routers using Dynamips (IOS on PowerPC), emulating a modular, high-end distribution switch like the Cisco Catalyst 4500 series is a different beast altogether. cisco 4500 switch ios download for gns3
You cannot simulate dual Sup engines in GNS3. Instead, deploy two IOL L3 switches and configure or GLBP and vPC (Where supported) or STP redundancy. To legally download Cisco switch images for GNS3,