This article serves as your complete, authoritative guide. We will cover everything from the legalities of IOS images, to where to find them, how to configure them for GNS3, and common pitfalls (like the infamous "CPU 100%" issue). By the end, you will have a fully functional 2960 switch running inside GNS3.

However, unlike routers, due to hardware architecture differences (most Catalyst switches use ASICs, not general-purpose CPU).

This leads to a confusing reality for users: You cannot simply load a generic 2960 IOS file into the standard GNS3 router node and expect it to work. To simulate a Cisco Catalyst 2960 in GNS3, you generally have two distinct paths: