Mininet

Mininet is an open-source network emulator that creates a realistic, shareable virtual network on a single machine. It is designed to facilitate rapid prototyping, testing, and experimentation with software-defined networking (SDN) and traditional networks without the need for dedicated hardware. It runs on Linux and is widely used in academia and industry to validate controllers, applications, and network designs.

Mininet achieves isolation and virtualization using Linux namespaces, cgroups, and virtual network devices. It relies on Open vSwitch for switching and OpenFlow to control packet forwarding. Virtual links are implemented with virtual Ethernet interfaces and traffic control to emulate bandwidth, delay, loss, and other characteristics. Topologies can be created programmatically or via a command-line tool; the tool can generate common structures such as linear, tree, and fat-tree networks.

Features include a Python API for programmatic topology construction, a command-line interface for interactive experimentation, and support for multiple SDN controllers (for example, POX, Floodlight, OpenDaylight, and Ryu). It also supports remote controllers, multiple hosts per switch, and integration with extensions such as Mininet-WiFi for wireless networks.

Typical workflow involves installing Mininet on a Linux system, creating a topology in Python or using the mn tool, starting the emulation, and running test scripts or SDN applications. It provides console access for testing and can export topology configurations for reproducibility.

Mininet is open source, released under the Apache License 2.0. Since its introduction in the early 2010s, it has become a standard tool in SDN research and education, enabling reproducible experiments and rapid iteration of network designs.