Emulator for rapid prototyping of Software Defined Networks
...We encourage you to contribute code, bug reports/fixes, documentation, and anything else that can improve the system! Links are virtual ethernet pairs, which live in the Linux kernel and connect our emulated switches to emulated hosts (processes).
The Common Open Research Emulator (CORE) is a tool for emulating networks on one or more machines. You can connect these emulated networks to live networks. CORE consists of a GUI for drawing topologies of lightweight virtual machines, and Python modules for scripting network emulation.