| Feature | GNS3 + IOU | GNS3 + Dynamips | GNS3 + QEMU (IOSv) | |--------|-----------|----------------|---------------------| | Boot speed | Very fast | Slow | Moderate | | RAM per node | ~128 MB | ~256 MB | ~512 MB+ | | Switching support | Good (L2 image) | Poor (no real switch) | Excellent | | Hardware accuracy | Low | High (CPU, bus) | Medium | | Ease of setup | Medium | Easy | Medium (needs VIRL images) |
Note: Cisco refers to modern Linux-compatible versions as IOL (IOS on Linux), but the "IOU" terminology is still widely used in the GNS3 community. Prerequisites for IOU in GNS3 iou gns3
Crucial. Because IOU is a native Linux application, it must run inside a Linux environment. The GNS3 VM (hosted on VMware or VirtualBox) acts as this environment. | Feature | GNS3 + IOU | GNS3
Here's an example of creating a simple network with two routers and two switches: The GNS3 VM (hosted on VMware or VirtualBox)
Before diving into the setup, ensure you have the following: Installed on Windows, macOS, or Linux.