Congrats to Mininet SIGCOMM 2018 Hackathon Winners!

Congratulations to Alexander Jung, Michał Król and Torsten Runge, who prototyped a Mininet node class for launching unikernels - small application-specific kernel images, basically an application linked with a library OS, ClickOS being one example - and ended up placing in the SIGCOMM 2018 Hackathon!

In their case they used Rumprun as the unikernel system and qemu/kvm to launch it. Branch: devel/rump

They are planning on continuing to work on it, so I hope we can get something simple and useful running and perhaps added to Mininet!

Mininet Wins ACM SIGCOMM SOSR Software Systems Award !

We are pleased to announce that Mininet has won the ACM SIGCOMM SOSR Software Systems Award!

“The ACM SIGCOMM SOSR Software Systems Award is given to an individual or an institution to recognize the development of a software system that has had a significant impact on SDN research, implementations, and tools. The impact may be reflected in the widespread adoption of the system, or of its underlying concepts, by the wider SDN community, either in research projects, in the open-source community, or commercially.”

The award also includes an invited talk, and the talk slides may be found here.

The SOSR 2017 program and proceedings may be found here.

Mininet’s ongoing success and impact would not be possible without the support and contributions from the Mininet community, so we’d like to take this opportunity to thank everyone and to say that we look forward to working together to continue to make Mininet a better and more useful system!

Mininet VM Security Advisory

Unfortunately, installing the Ubuntu SSH package into a VM image causes default SSH keys to be generated. In the case of the Mininet VM, this means that the VM images for Mininet 2.2.1 and earlier included the same set of default SSH keys (which could leave you open to a MITM attack.) This probably isn’t surprising to many of you, but we’re changing it in the Mininet VM images to avoid this issue.

As of Mininet 2.2.2, we no longer ship default SSH keys in the provided Mininet VM; we remove them before upload, and new SSH keys should be generated the first time you boot a Mininet 2.2.2 VM image.

If you are logging into an older Mininet VM over the internet or another non-secure network, we highly recommend regenerating your SSH keys if you haven’t done so already:

sudo rm -f /etc/ssh/*key*
sudo /usr/sbin/dpkg-reconfigure openssh-server
sudo service ssh restart

Alternately, you are welcome to download a new Mininet 2.2.2 VM image.

If you’re distributing a VM image for any purpose, we recommend removing any SSH keys before uploading it!

Additional information on Mininet 2.2.2 may be found at

Announcing Mininet 2.2.2

Mininet 2.2.2 is primarily a performance improvement and bug fix release.

Security Advisory!

  • The Mininet VM images no longer ship with identical ssh keys. We recommend that you destroy any default ssh keys in existing Mininet VMs if you haven’t already:
sudo rm -f /etc/ssh/*key*
sudo /usr/sbin/dpkg-reconfigure openssh-server
sudo service ssh restart

Improvements and Bug Fixes

  • We now run public CI builds via Travis
  • Several common test failures have been addressed
  • We use our own forked versions of oflops and the Stanford Reference Switch/Controller
  • now has basic support for RHEL
  • mnexec now works on systemd systems
  • The default OpenFlow port is now the official port of 6653 rather than the classic port of 6633, which was nastily co-opted by Cisco.
  • Several issues with the NAT element have been addressed

Bugs and Gotchas

  • Ubuntu 16.04 LTS (Xenial) kernel bug: the problem resulting in unregister_netdevice: waiting for lo to become free. Usage count = 1 in the console or kernel log has returned. We recommend using 14.04 or an older kernel until this is fixed.
  • Ryu installation with -y is still broken
  • The --tests option is slightly different from mainline

Release notes and Downloads

Full release notes for this release and previous releases may be found in the Release Notes on

The easiest way to get started with Mininet is to download a VM image.

Download, installation, and upgrade instructions may be found at .

The latest Mininet source code is available on github and also via


Thanks to all of the contributors of fixes and enhancements for this release, including Olivier Tilmans, Jono Hart, Tomasz Buchert, Rahman Pujianto, Roan Huang, M S Vishwanath Bhat, Brian O’Connor, and others.

Automated Testing Using Travis CI

Mininet is now using Travis CI for automated testing!

Whenever code is pushed to Mininet, Travis CI starts a test job that installs Mininet, runs a simple sanity test, and the “quick” tests for HiFi, the walkthrough, and the example code.

The full results are available on Travis CI’s Mininet page, and the status of the most recent master build is part of the README on Github:

Travis CI also verifies all new pull requests and displays their build status in the pull request discussion.

Mininet will continue to be tested in several ways on private servers, but our hope is that having a public-facing CI will give members of the community a better sense of how Mininet is tested and the quality of the codebase. Furthermore, we hope that by automatically testing pull requests, we will reduce the likelihood of merging broken code and reduce the testing burden on maintainers.

Announcing Mininet 2.2.1

Mininet 2.2.1 is primarily a performance improvement and bug fix release.

  • Batch startup has been implemented for Open vSwitch, improving startup performance.

  • OVS patch links have been implemented via OVSLink and --link ovs

    Warning! These links have serious limitations compared to virtual Ethernet pairs: they are not attached to real Linux interfaces so you cannot use tcpdump or wireshark with them; they also cannot be used in long chains - we don’t recommend more than 64 OVSLinks, for example --linear,64. However, they can offer significantly better performance than veth pairs, for certain configurations.


  • You can now easily install Mininet on a Raspberry Pi (simply by using -fnv or -a) ;-)

  • mn now accepts multiple --controller arguments

  • --controller remote and RemoteController now accept ip arguments of the form <IP address>:<port> (in addition to ip=<IP>,port=<port>)

Additional information for this release and previous releases may be found in the Release Notes on

The easiest way to get started with Mininet is to download a VM image.

Download, installation, and upgrade instructions may be found at .

The latest Mininet source code is available on github and also via

Thanks to all of the Mininet contributors! A number of interesting features and improvements are already in the works for Mininet 2.3.

Mininet on Raspberry Pi

Mininet is now easy to install on the Raspberry Pi running Debian/Raspbian 7 Wheezy!

Mininet’s has been updated so it should simply work: -fnv  ## basic install -a    ## the works

Here is an example of Mininet running on a Raspberry Pi 2 model B:

A Raspberry Pi can be used any time you need a cheap network-in-a-box, for example for courses, laboratories, demonstrations, or simple experiments.

We look forward to hearing (on mininet-discuss and elsewhere) about interesting, fun and clever uses of Mininet running on the Pi !!

Announcing Mininet 2.2.0 !

We are pleased to announce Mininet 2.2.0! This release provides a number of bug fixes as well as several new features, including:

  • Improved OpenFlow 1.3 support

    • mn --switch ovs,protocols=OpenFlow13 starts OVS in 1.3 mode
    • -w installs 1.3-compatible Wireshark dissector using Loxigen
      • -y installs the Ryu 1.3-compatible controller
  • A new node library, and new Node types including LinuxBridge, OVSBridge, LinuxRouter (see examples/) and NAT

  • Easier LAN/internet connectivity from Mininet hosts

    • mn --nat will semi-automatically connect a Mininet network to your LAN using NAT, solving the “why can’t I ping Google?” problem.

      Warning: By default this will reroute local traffic originating at your Mininet server or VM and destined for Mininet’s IP subnet ( by default) to the Mininet network, which can break connectivity if you are using addresses in the same range in your LAN. You can change this range using the --ipbase option.

  • An improved MiniEdit GUI (examples/ - thanks to Gregory Gee

  • Support for multiple --custom arguments to mn

    mn --custom, --topo mytopo --switch myswitch

  • Experimental cluster support - consult the documentation for details - as well as examples/ and an experimental --cluster option for topologies built with the default Host and OVSSwitch classes:

    mn --cluster localhost,server1,server2,server3 --topo tree,4,4

Note that examples contain experimental features which might “graduate” into mainline Mininet in the future, but they should not be considered a stable part of the Mininet API!

How to get it

The easiest way to get started with Mininet is to download a VM image. See for details.

The latest Mininet source code is available on github and also via

Additional information on the Mininet 2.2.0 release may be found in the release notes and on

Mininet is an open source project, and we are grateful to our many code contributors, bug reporters, and active users who continue to help make Mininet a useful system with a friendly and helpful community!

Have fun with Mininet!

Mininet 2.2.0 Core Team:
Bob Lantz, Brian O’Connor, Cody Burkard
Open Networking Laboratory