TechKnowSurge
TechKnowSurge Catalog Videos SDN Data and Control Planes
VideoSecurityFree

SDN Data and Control Planes

Software-defined networking separates the data plane, which handles the physical forwarding of traffic between devices, from the control plane, which governs how that traffic flows and is managed by a centralized SDN controller.

⚑ Complete this video to capture a CTF flag worth 1 point.

About this video

Software-defined networking is an approach to network design that virtualizes infrastructure by separating two core functional layers: the data plane and the control plane. The data plane encompasses the hardware and associated software responsible for physically forwarding traffic from device to device across the network. The control plane, by contrast, is the software layer that makes decisions about how traffic flows, determining routing logic and network behavior rather than handling packets directly. Together, these two planes allow the network to be managed in a far more dynamic and flexible way than traditional hardware-centric architectures permit. Central to the SDN model is the SDN controller, a dedicated software component that operates at a higher level of abstraction above the individual network devices. Administrators configure the desired traffic flow parameters at the controller level, and the controller translates those policies into device-specific instructions pushed down to each switch or router. This centralized model eliminates the need to manually configure each device in isolation and allows the network to adapt routing and forwarding behavior based on a unified, policy-driven framework. The same principles apply directly to SD-WAN deployments, where physical Layer 3 routers handle data-plane forwarding across geographically distributed links while the control plane centrally governs path selection, failover logic, and device configuration across the entire wide area network.

What you'll learn

What's covered

Software-Defined Networking

Key terms

Software-defined Network
SDN
A network architecture that decouples the control plane from the data plane, enabling centralized, programmable network management through software controllers rather than individual device configuration. SDN allows network behavior to be dynamically adjusted through software, simplifying management and enabling rapid provisioning.
Data Plane
The part of a network device responsible for actually forwarding packets toward their destinations based on rules and tables built by the control plane. In a router, the data plane looks up each packet's destination in the forwarding table and sends it out the correct interface at high speed.
Control Plane
The part of a network device responsible for making routing and policy decisions, such as running routing protocols to build and maintain the routing table, which the data plane then uses to forward traffic. The control plane handles the intelligence of the network while the data plane handles the actual packet forwarding.
SDN Controller
A centralized software component in an SDN architecture that manages network device configuration and determines traffic flow across the network.
Router
A network device that forwards data packets between networks based on IP addresses.
Switch
A network device that connects devices within a LAN and forwards traffic based on MAC addresses.

Topics

Software Defined Networking Sdn Controller Data Plane Control Plane Network Architecture Networking

Transcript

The data plane and the control plane

Software-defined networking has a data plane and a control plane. Software-defined networking makes our networks much more dynamic, and essentially I like to think about it as virtualizing the network. But how does it do that? It uses these concepts of a data plane and a control plane.

The data plane is how that data gets forwarded on from device to device, versus the control plane, which allows control of how things are going to function on the network.

Here we have the hardware, and perhaps there's some software that helps control that hardware, that happens on the data plane there. But essentially what we have is this hardware that's doing the forwarding and sending the information back and forth between these switches. And then we have the control plane, and that is the software that's running on here that's actually making the decisions on how this flow is going to happen.

The SDN controller

We also have an SDN controller. This is a separate piece of software here that does the controlling from an upper level. So now what we have is we set the configurations at this upper level here, and then it will configure the software that's running on each one of these devices so that the information flows. What we have to do is go and set up the controller with the parameters of how we want the information to flow, and then it will figure out the best way to network this and set up the networking accordingly.

SD-WAN

This is also how SD-WAN works. Here we have routers, which are operating at layer three, so we've got them all physically attached to each other, and the data plane is sending that information back and forth. But what paths it's going to take and what is set up on here is going to be controlled by the control layer here, which is controlled by this software, which is going to give instructions to each one of these devices.

About TechKnowSurge

TechKnowSurge builds IT and cybersecurity professionals through hands-on, concept-first training built around real understanding — not memorization. Free interactive tools, structured programs, and 25+ years of real-world experience, all in one place.

Explore free tools and programs →