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Example: Enabling OpenFlow on EX4550 Switches

OpenFlow is an open standard that allows you to control traffic paths in a network by creating, deleting, and modifying flows in each device, including EX4550 switches, along a path. This example shows how to configure OpenFlow support on an EX4550 switch.

Requirements

This example uses the following hardware and software components:

  • An EX4550 switch running Junos OS Release 13.2X51-D15 or a later release.

  • An OpenFlow software package with a software package release that matches the Junos OS release of the device on which it is installed.

  • A TCP connection between the switch and an OpenFlow controller, which needs to access the data plane of the switch.

  • A connection between the me0 interface of the switch and the management network.

Overview

In this example, you configure support for OpenFlow on an EX4550 switch. The switch has three interfaces that are dedicated to handling OpenFlow traffic: xe-0/0/4.0, xe-0/0/5.0, and xe-0/0/6.0. Note that on EX4550 switches, you can only configure a single logical unit using logical unit number 0 for OpenFlow interfaces.

In an OpenFlow topology, a virtual switch is used to isolate and control OpenFlow traffic. You configure the OpenFlow virtual switch and OpenFlow protocol statements at the [edit protocols openflow] hierarchy level. In this example, the virtual switch, 100, is assigned a default VLAN, which acts as a logically separate flood domain. The assignment of the default VLAN to virtual switch 100 is automatic, and no configuration is required to set up the default VLAN.

Virtual switch 100 also connects to the controller over a TCP connection at the IP address 198.51.100.174. The virtual switch configuration must include all of the logical interfaces participating in OpenFlow, and OpenFlow traffic will only enter or exit from these interfaces.

A flow entry consists of a match condition against which packets entering an OpenFlow interface are compared, and the action that is applied to packets that match the condition. Each OpenFlow interface can have one or more flow entries. The default-action statement in the OpenFlow configuration indicates the action the switch applies to packets that do not have a matching flow entry. If you omit the default-action statement, the default action is packet-in, which means that packets that have no matching flow entry are sent to the controller for processing. This example explicitly configures packet-in as the default action for packets that do not have a matching flow entry.

This example also configures OpenFlow traceoptions, along with the flag all statement, which is meant to capture and log all OpenFlow events. Since the example does not configure a specific filename for the log file, OpenFlow events are logged in the default OpenFlow log directory /var/log/ofd.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, copy and paste the commands into the CLI at the [edit] hierarchy level, and then enter commit from configuration mode.

Procedure

Step-by-Step Procedure

To configure support for OpenFlow:

  1. Configure the OpenFlow interfaces as Layer 2 interfaces.

  2. Configure an OpenFlow virtual switch.

  3. Configure the OpenFlow controller IP address and the connection protocol.

  4. Configure the logical interfaces participating in OpenFlow under this virtual switch.

  5. Configure the default action for packets that do not have a matching flow entry.

  6. Configure OpenFlow traceoptions.

  7. Commit the configuration.

Results

From operational mode, confirm your configuration by entering the show configuration interfaces and show configuration protocols openflow commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Verification

Confirm that the configuration is working properly.

Verifying that the OpenFlow Controller Connection is Up

Purpose

Verify that the OpenFlow controller connection is up.

Action

Issue the show openflow controller operational mode command, and verify that the controller connection state is up. Because the virtual switch configuration has only a single controller, the virtual switch should automatically initiate a connection to the controller after you commit the configuration.

Meaning

The output shows that the connection state of the OpenFlow controller is up, in addition to other information about the controller.

Verifying that the OpenFlow Interfaces Are Up

Purpose

Verify that the OpenFlow interfaces are in the Up state.

Action

Issue the show openflow interfaces operational mode command, and verify that the state of each OpenFlow interface is Up.

Meaning

The output shows that the state of the OpenFlow interfaces is Up, in addition to other information about the interfaces.