# GNS3 GNS3 is a software for managing virtual networking devices (Cisco IOS, etc) # Configuration There is a bug with saving changes from GNS3's GUI to the server config. Changes have to be done manually for now. Config file is at ``~/.config/GNS3/3.0/gns3_server.conf`` # Dynamips Dynamips are regular cisco MIPS architecture router images that can be emulated with GNS3. ## Idle PC value This helps reduce CPU usage massively. With the correct value you can run dozens of routers/switches on modest hardware without massive CPU spikes. To find a good Idle PC value: 1. Boot up the node and let it boot fully. 2. Do a 'copy run start'. Restart the device, don't calculate idle value on first boot 3. Only have the target node running, then click 'Idle-PC' and try each one, comparing CPU usage with something like btop. Source https://community.infosecinstitute.com/discussion/110541/any-solution-to-gns3-dynamips-high-cpu-usage # IOU IOU images are IOS-on-Unix images meant for internal Cisco use. Currently, it seems that on Arch Linux GNS3 doesn't support IOU images since there is no gns3-iou package. @research Manually install package from deb file? # Docker containers GNS3 has support for managing and connecting docker containers to a topology. These are lighter than full blown QEMU VMs but less versatile. See on how to setup docker containers in GNS3. See on gns3 tailored docker images. Image links -----------