OpenFlow is a vendor-neutral, standard communications interface defined to enable the interaction between the control and forwarding channels of an SDN architecture. The OpenFlowPlugin project intends to support implementations of the OpenFlow specification as it evolves. It currently supports OpenFlow versions 1.0 and 1.3.2. In addition, to support the core OpenFlow specification, OpenDaylight Beryllium also includes preliminary support for the table type patterns and OF-CONFIG specifications.

The OpenFlow southbound plugin currently provides the following components:

• Flow management
• Group management
• Meter management
• Statistics polling

Let's connect an OpenFlow switch to OpenDaylight.

This recipe requires an OpenFlow switch. If you don't have any, you can use a Mininet-VM with OvS installed. You can download Mininet-VM from the following website:

https://github.com/mininet/mininet/wiki/Mininet-VM-Images

Any version should work.

The following recipe will be presented using a Mininet-VM with OvS 2.0.2.

Perform the following steps:

1. Start the OpenDaylight distribution using the karaf script. Using this script will give you access to the Karaf CLI:

$ ./bin/karaf

2. Install the user-facing feature responsible for pulling in all dependencies needed to connect an OpenFlow switch:

opendaylight-user@root>feature:install odl-openflowplugin-all  

It might take a minute or so to complete the installation.

3. Connect an OpenFlow switch to OpenDaylight.

As mentioned in the Getting ready section, we will use Mininet-VM as our OpenFlow switch as this VM runs an instance of OpenVSwitch:

mininet@mininet-vm:~$ sudo ovs-vsctl add-br br0  

mininet@mininet-vm:~$ sudo ovs-vsctl set-controller br0 tcp: ${CONTROLLER_IP}:6633  

mininet@mininet-vm:~$ sudo ovs-vsctl show
0b8ed0aa-67ac-4405-af13-70249a7e8a96
  Bridge "br0"
    Controller "tcp: ${CONTROLLER_IP}:6633"
      is_connected: true
    Port "br0"
      Interface "br0"
        type: internal
  ovs_version: "2.0.2"  

Once the feature is installed, OpenDaylight is listening to connections on port 6633 and 6640. Setting up the controller on the OpenFlow-capable switch will immediately trigger a callback on OpenDaylight. It will create the communication pipeline between the switch and OpenDaylight so they can communicate in a scalable and non-blocking way.