Downloading a Cisco 2960 IOS image for GNS3 is a bit different from downloading standard software because Cisco's Operating Systems are proprietary and require a valid service contract (Cisco Connection Online - CCO) to access legally.
Edit > Preferences > QEMU (for GNS3 versions that use QEMU for switches).New and select the IOS image you've downloaded.| Filename | Type | Best For | Spanning Tree | L2 Security | | :--- | :--- | :--- | :--- | :--- | | | IOL (L2) | CCNA/CCNP Switching | Full Support | Full Support | | i86bi_linux_l2-adventerprisek9-ms | IOL (L2) | Older Builds | Good | Good | | c2960-lanbasek9-mz.150-2.SE | Real IOS | Physical HW only | N/A (Doesn't boot) | N/A | cisco 2960 switch ios download for gns3
: These are specialized "L2" (Layer 2) images designed to run as software. They provide nearly all 2960/3750 switching features and are the standard for GNS3 switching. Cisco VIRL / CML (Cisco Modeling Labs) Images Downloading a Cisco 2960 IOS image for GNS3