Mininet: Rapid Prototyping for Software Defined Networks

The best way to emulate almost any network on your laptop!

Version 2.1.0

What is Mininet?

Mininet emulates a complete network of hosts, links, and switches on a single machine. To create a sample two-host, one-switch network, just run:

sudo mn

Mininet is useful for interactive development, testing, and demos, especially those using OpenFlow and SDN. OpenFlow-based network controllers prototyped in Mininet can usually be transferred to hardware with minimal changes for full line-rate execution.

How does it work?

Mininet creates virtual networks using process-based virtualization and network namespaces - features that are available in recent Linux kernels. In Mininet, hosts are emulated as bash processes running in a network namespace, so any code that would normally run on a Linux server (like a web server or client program) should run just fine within a Mininet "Host". The Mininet "Host" will have its own private network interface and can only see its own processes. Switches in Mininet are software-based switches like Open vSwitch or the OpenFlow reference switch. Links are virtual ethernet pairs, which live in the Linux kernel and connect our emulated switches to emulated hosts (processes).

Features

Mininet includes:

• A command-line launcher (mn) to instantiate networks.

• A handy Python API for creating networks of varying sizes and topologies.

• Examples (in the examples/ directory) to help you get started.

• Full API documentation via Python help() docstrings, as well as the ability to generate PDF/HTML documentation with make doc.

• Parametrized topologies (Topo subclasses) using the Mininet object. For example, a tree network may be created with the command:

  mn --topo tree,depth=2,fanout=3

• A command-line interface (CLI class) which provides useful diagnostic commands (like iperf and ping), as well as the ability to run a command to a node. For example,

  mininet> h11 ifconfig -a

  tells host h11 to run the command ifconfig -a

• A "cleanup" command to get rid of junk (interfaces, processes, files in /tmp, etc.) which might be left around by Mininet or Linux. Try this if things stop working!

  mn -c

New features in 2.1.0

Mininet 2.1.0 provides a number of bug fixes as well as a number of new features, including:

• Convenient access to Mininet() as a dict
• X11 tunneling (wireshark in Mininet hosts!)
• Accurate reflection of the Mininet() object in the CLI
• Automatically detecting and adjusting resource limits
• Automatic cleanup on failure of the mn command
• Support for running OVS in user space mode
• Preliminary support for the Indigo Virtual Switch (IVSSwitch)
• The ability to import examples as modules

We have provided several new examples which can also be imported to provide useful functionality, including:

• A simple NAT script to attach Mininet networks to your LAN
• An example of modeling control and data networks
• An example of per-host custom directories using bind mounts

Note that these are experimental features which may "graduate" into mainline Mininet in the future, so they should not be considered a stable part of the Mininet API!

Installation

See INSTALL for installation instructions and details.

Documentation

In addition to the API documentation (make doc), much useful information, including a Mininet walkthrough and an introduction to the Python API, is available on the Mininet Web Site. There is also a wiki which you are encouraged to read and to contribute to, particularly the Frequently Asked Questions (FAQ.)

Support

Mininet is community-supported. We encourage you to join the Mininet mailing list, mininet-discuss at:

https://mailman.stanford.edu/mailman/listinfo/mininet-discuss

Contributing

Mininet is an open source project and is currently hosted at https://github.com/mininet. You are encouraged to download the code, examine it, modify it, and submit bug reports, bug fixes, feature requests, new features and other issues and pull requests. Thanks to everyone who has contributed to the project (see CONTRIBUTORS for more info!)

Best wishes, and we look forward to seeing what you can do with Mininet to change the networking world!

Credits

The Mininet 2.1.0 Team:

• Bob Lantz
• Brian O'Connor