OpenFlow Support
in lighty.io

What is OpenFlow?

OpenFlow enables network controllers to determine the path of network packets across a network of switches. It separates the control plane from the forwarding plane, allowing more sophisticated traffic management than ACLs and routing protocols alone.

OpenFlow allows switches from different vendors — each with their own proprietary interfaces — to be managed remotely using a single, open protocol. Controllers listen on TCP port 6653 for switch connections (legacy: 6633). The protocol uses TLS for security.

lighty.io Application Bootstrap

The OpenFlow example application follows the standard lighty.io startup pattern:

// 1. Initialize and start Lighty controller
final LightyControllerBuilder lightyControllerBuilder = new LightyControllerBuilder();
final LightyController lightyController = lightyControllerBuilder
    .from(controllerConfiguration).build();
lightyController.start().get();

// 2. Start RESTCONF server
final CommunityRestConfBuilder communityRestConfBuilder = new CommunityRestConfBuilder();
final CommunityRestConf communityRestConf = communityRestConfBuilder
    .from(RestConfConfigUtils.getRestConfConfiguration(
        restConfConfiguration, lightyController.getServices()))
    .build();
communityRestConf.start();

// 3. Start OpenFlow southbound plugin
final OpenflowSouthboundPlugin plugin = new OpenflowSouthboundPluginBuilder()
    .from(configuration, lightyController.getServices())
    .withPacketListener(new PacketInListener())
    .build();
plugin.start();

Configuration

OpenFlow configuration is passed as JSON. Key parameters include statistics polling, barrier timeouts, thread pool sizing, and switch SSL settings:

{
  "openflow": {
    "isStatisticsPollingOn": true,
    "barrierCountLimit": "1234",
    "echoReplyTimeout": "4000",
    "globalNotificationQuota": "9000",
    "useSingleLayerSerialization": "true",
    "switchConfig": {
      "instanceName": "openflow-switch-connection-provider-default-impl",
      "port": 1234,
      "transportProtocol": 0,
      "switchIdleTimeout": 15001
    }
  }
}

Connecting a Device with Mininet

After starting the controller, connect an OpenFlow device using Mininet:

sudo mn --controller=remote,ip=127.0.0.1 --topo=tree,1 --switch ovsk,protocols=OpenFlow13

The controller log confirms device mastery:

INFO [main] (Main.java:100) - Lighty and OFP started in 7649.765ms
INFO [nioEventLoopGroup-10-2] (ContextChainHolderImpl.java:225) - Role MASTER was granted to device openflow:1

Post a Flow Rule

curl -X POST -k \
  -H 'Content-Type: application/xml' \
  -H 'Authorization: Basic YWRtaW46YWRtaW4=' \
  https://localhost:8888/restconf/operations/sal-flow:add-flow \
  --data '<input>...</input>'

Verify Device State

curl -X GET -k \
  -H 'Authorization: Basic YWRtaW46YWRtaW4=' \
  'https://localhost:8888/restconf/data/opendaylight-inventory:nodes/node=openflow%3A1/table=0?content=nonconfig'

The response will show the installed flow table including your posted rule, match fields, instructions, and statistics — confirming the device is correctly connected and managed.

OpenFlow Capabilities

• Remote administration of layer 3 switch packet forwarding tables
• Add, modify, and remove packet matching rules and actions
• Configurable flow rule lifespan — rules expire or persist as needed
• Unmatched packets can be forwarded to the controller for decision
• Controller can redeploy rules to prevent structural flows between switch and controller
• Layered on TCP with TLS for secure control-plane communication

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