Develop simulations for networks of different levels of complexity. Emulate the work of one or several routers and customize all port, connection, and access parameters. The suite includes different interconnected emulation modules: VirtualBox, Qemu, and Dynamips.
GNS3 2.2.43 for Mac is available as a free download on our application library. This app's bundle is identified as net.gns3. The actual developer of this free Mac application is GNS-3 Team. The default filename for the program's installer is gns3-0.8.6-osx-lion.dmg.
GNS3 can be installed on Mac OS X 10.5 or later. Our built-in antivirus checked this Mac download and rated it as virus free. The most popular versions of GNS3 for Mac are 1.2, 0.8 and 0.5. The software is included in Internet & Network Tools. The size of the latest installation package available for download is 111.6 MB.
From the developer:
GNS3 is a graphical network simulator that allows simulation of complex networks.
To allow complete simulations, GNS3 is strongly linked with :
Dynamips, the core program that allows Cisco IOS emulation.
Dynagen, a text-based front-end for Dynamips.
Qemu, a generic and open source machine emulator and virtualizer.
You may want to check out more software for Mac, such as gs3-server, which might be similar to GNS3.