Building a home lab is an excellent way for network enthusiasts to explore technologies and concepts that power today’s dynamic networking environments. Software Defined Networking (SDN) is gaining prominence for its powerful capabilities in simplifying and optimizing network infrastructures. If you’re keen on integrating SDN concepts into your home lab, you’re on the right path. This guide will walk you through setting up an SDN-controlled network using popular open-source tools.

Prerequisites

Before diving in, ensure you have the following:

  • A machine or a VM with a hypervisor installed (VirtualBox, VMware, etc.).
  • Basic networking knowledge.
  • Familiarity with Linux commands.
  • Internet connection for downloading necessary components.

Setting Up Your SDN Environment

We will use Mininet to simulate a network and OpenDaylight (ODL) as the SDN controller.

Step 1: Install Mininet

Mininet is a network emulator which allows you to create a realistic virtual network on your machine. Here’s how you can install it on Ubuntu:

sudo apt-get update
sudo apt-get install mininet

Step 2: Install OpenDaylight Controller

OpenDaylight is an open-source SDN controller platform that provides a framework for network control automation.

  1. Download OpenDaylight:
wget https://nexus.opendaylight.org/content/repositories/public/org/opendaylight/integration/karaf/<version>/karaf-<version>.tar.gz

Replace <version> with the specific version number you wish to install. Extract the downloaded file:

tar -xvf karaf-<version>.tar.gz
cd karaf-<version>/bin
  1. Start OpenDaylight:
./karaf

Once Karaf OS is running, install the necessary features:

feature:install odl-l2switch-switch

Step 3: Simulate Network with Mininet

With Mininet ready, let’s simulate a basic topology and connect it to the OpenDaylight controller:

sudo mn --controller=remote,ip=<controller-ip>,port=6653 --topo tree,depth=2,fanout=2

Step 4: Verify Connection

To confirm that your Mininet network is correctly interacting with OpenDaylight, check if the hosts can communicate:

mininet> pingall

You should see 0% packet loss, indicating successful communication among hosts under control of an SDN controller.

Advanced Configurations

Network Flow Management

OpenDaylight makes managing flows straightforward. You can apply rules to prioritize certain types of traffic. Use REST API to interact with this:

curl -X POST -H "Content-Type: application/json" \
-d "{ \"flow-node-inventory:flow\": [{...}]}" \
http://<controller-ip>:8181/restconf/config/opendaylight-inventory:nodes/

Dynamic Network Adjustment

One of SDN’s strengths is dynamic adaptation. Here’s how you could programmatically adjust traffic using OpenDaylight:

import requests

url = "http://<controller-ip>:8181/restconf/operations/sal-flow:add-flow"
headers = {
    'Content-Type': "application/json",
    'Authorization': "Basic <auth-token>"
}

payload = {
    "input": {
        "flow-node-inventory:priority": 100,
        "flow-node-inventory:cookie": 1,
        // Other flow properties
    }
}

requests.request("POST", url, data=payload, headers=headers)

Conclusion

Creating a Software Defined Network in a home lab is not only viable but rewarding. You’ll gain insights into network configurations and control that go beyond physical networking. With tools like Mininet and OpenDaylight, the possibilities are endless. Don’t hesitate to experiment further, perhaps by incorporating more complex topologies or integrating additional SDN controllers.

As you expand your home lab, consider exploring other SDN controllers like ONOS or Ryu, and delve deeper into areas such as network function virtualization (NFV). Happy networking!