Sample Workflow

Mininet is designed you to quickly create, interact with, customize and share a software defined network prototype, and provides a smooth path to running on hardware. This page illustrates the basic Mininet workflow, and many additional details are available in the Mininet walkthrough, the OpenFlow tutorial, and Mininet documentation.

Creating a Network

You can create a network with a single command. For example,

mn --switch ovsk --controller nox --topo tree,depth=2,fanout=8 --test pingAll

starts a network with a tree topology of depth 2 and fanout 8 (i.e. 9 switches connecting 64 hosts), using Open vSwitch switches under the control of NOX, and runs the pingAll test to check connectivity between every pair of nodes.

Interacting with a Network

Mininet's CLI allows you to control and manage your entire virtual network from a single console. For example, the CLI command

mininet> h2 ping h3

tells host h2 to ping host h3 's IP address.

Customizing a Network

Mininet's API allows you to create custom networks with a few lines of Python. For example, the following script

from mininet.net import Mininet
from mininet.topolib import TreeTopo
tree4 = TreeTopo(depth=2,fanout=2)
net = Mininet(topo=tree4)
net.start()
h1, h4  = net.hosts[0], net.hosts[3]
print h1.cmd('ping -c1 %s' % h4.IP())
net.stop()

creates a small network (4 hosts, 3 switches), and pings one host from another (in about 4 seconds with the current version.)

The Mininet distribution includes several text-based and graphical (see above) applications which we hope will be instructive and inspire you to create cool and useful apps for your own network designs.

Sharing a Network

Mininet is distributed as a virtual machine (VM) image with all dependencies pre-installed, runnable on common virtual machine monitors such as VMware, Xen and VirtualBox. This provides a convenient container for distribution; once a prototype has been developed, the VM image may be distributed to others to run, examine and modify. A complete, compressed Mininet VM is about 800 MB. (Mininet can also be installed natively on Linux distributions that ship with CONFIG_NET_NS enabled, such as Ubuntu 10.04+, without replacing the kernel.) If you are reading a great SIGCOMM (or other) paper about a Software-Defined Network, wouldn't you like to be able to click, download and run a living, breathing example of the system? If so, consider developing a Mininet version of your own system that you can share with others. (Alternately, if you fear others reproducing - and possibly contradicting - your published results, an easily shared and downloaded version of your system may not be desirable!)

Running on Hardware

Once a design works on Mininet, it can be deployed on hardware for real-world use, testing and measurement.

To successfully port to hardware on the first try, every Mininet-emulated component must act in the same way as its corresponding physical one. The virtual topology should match the physical one; virtual Ethernet pairs must be replaced by link-level Ethernet connectivity. Hosts emulated as processes should be replaced by hosts with their own OS image. In addition, each emulated OpenFlow switch should be replaced by a physical one configured to point to the controller. However, the controller does not need to change. When Mininet is running, the controller ``sees" a physical network of switches, made possible by an interface with well-defined state semantics.