Historically, GNS3 used to emulate Cisco hardware. However, Dynamips only supports MIPS-based platforms like the Cisco 7200, 3700, and 2600 series. The Catalyst 4500 series uses a different architecture that Dynamips cannot emulate.
Finding a legitimate Cisco Catalyst 4500 IOS image for GNS3 can be tricky because these specific switch images are often hardware-dependent and not natively emulated like older routers.
Unlike the ubiquitous 7200 or 3640 routers, the Catalyst 4500 series (Sup6, Sup7, Sup8) runs on IOS-XE or classic IOS, but with a massive catch:
Initializing memory...
Below is a draft for a guide or post explaining how to handle this. 🚀 Guide: Getting Cisco Switching to Work in GNS3
Cisco 4500 switch IOS download for GNS3