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.