Phocean.net / Computer Security

GNS3 and Dynamips put together give a nice open-source and free alternative to emulate a network with IOS routers. Dynampis is an emulator of Cisco 7200 router, while GNS3 provides a nice graphical environment to design your network and use the virtual routers. I sometimes use Boson Netsim, which is not only non-free but not [...]