gns3: GNS3 (A Graphical Network Simulator) gns3: gns3: GNS3 is a graphical network simulator that allows simulation of gns3: complex networks.To allow complete simulations, GNS3 is strongly gns3: linked with: gns3: Dynamips, the core program that allows Cisco IOS emulation. gns3: Dynagen, a text-based front-end for Dynamips. gns3: Pemu, a Cisco PIX firewall emulator based on Qemu. gns3: gns3: Homepage: http://www.gns3.net gns3: