QEMU is the modern backbone of GNS3. It runs official, vendor-packaged virtual appliances (like Cisco IOSv, Palo Alto, and Fortinet) inside the GNS3 Virtual Machine.
| Category | Supported Vendors & Products | |---|---| | | Cisco IOS (1700, 2600, 2691, 3600, 3700, 7200 series) | | Virtual Routers | Cisco IOU L3, Cisco vIOS, Cisco CSR | | Switches | Cisco IOU L2, IOSvL2, Nexus Switches | | Firewalls | Cisco ASA (ASAv), Fortinet, Palo Alto, Check Point | | Advanced Platforms | Cisco ISE, Cisco FirePOWER, Cisco SD-WAN (Viptela), Cisco XRv | | Server OS Images | Windows, Linux, ESXi |
Go to Edit > Preferences > IOS on UNIX . gns3 full pack images
IOS on Unix (IOU), also known as IOS on Linux (IOL), represents Cisco IOS compiled directly as a user-mode program for Linux architectures. These images are highly prized in full packs because they consume minimal system resources while offering advanced Layer 2 (switching) and Layer 3 (routing) features. 3. Qemu/KVM Appliance Images
This ISO contains an official "full pack" of pristine, updated images optimized for virtualization, including: QEMU is the modern backbone of GNS3
These are legacy images (e.g., 3725, 7200) used for basic routing and switching labs. They require low resources but cannot simulate modern features. CCNA, basic CCNP labs. 2. Cisco IOSv and IOSv-L2 (Virtual IOS)
Idle-PC values are unique to each IOS image. Once you find a working value for a particular image, GNS3 will remember it for all future instances of that same image. IOS on Unix (IOU), also known as IOS
The import wizard will display a list of compatible file names and MD5 checksums.
These images form the backbone of many GNS3 labs, allowing users to build everything from small branch office topologies to complex enterprise core networks.
Mega and Google Drive impose bandwidth limits on free-tier users, which can interrupt large downloads.
The GNS3 Marketplace provides official appliance templates that for various devices. These templates have been thoroughly tested and include recommended settings, significantly reducing configuration errors and setup time. The appliances are using GNS3 recommended settings and have been thoroughly tested. After downloading the appliance template, you'll need to provide your own images for licensed systems like Cisco IOS, as GNS3 cannot distribute copyrighted vendor images.