Software Defined Networking: Avoid Top SDN Control Plane Mistakes
September 5, 2025
Software defined networking (SDN) is changing how businesses manage and scale their IT infrastructure. If you're looking to simplify your network operations, improve performance, and reduce costs, SDN offers a flexible and centralized way to do it. In this blog, you'll learn what SDN is, how it works, common mistakes to avoid, and how to plan a smooth SD-WAN implementation. We'll also cover key features, benefits, and practical tips to help you configure and deploy SDN effectively.
Understanding software defined networking
Software defined networking separates the control plane from the data plane, allowing IT teams to manage network traffic through a centralized controller. This makes it easier to automate tasks, adjust configurations, and respond to changing business needs without touching every router or switch manually.
SDN also supports better scalability and security. By abstracting the network infrastructure, you can configure policies and monitor performance from a single dashboard. This is especially useful in large data centers or virtualized environments where traditional network architectures can become complex and hard to manage.
Common mistakes to avoid when adopting SDN
Before you jump into SDN, it's important to understand what can go wrong. Here are some common mistakes businesses make during SDN deployment and how to avoid them.
Mistake #1: Skipping a detailed network assessment
Many businesses rush into SDN without fully understanding their current network setup. This can lead to compatibility issues and poor performance. Always start with a full network audit to identify what needs to change.
Mistake #2: Ignoring SDN controller redundancy
The controller is the brain of your SDN. If it fails and there's no backup, your entire network could go down. Make sure you have a redundant controller setup to avoid single points of failure.
Mistake #3: Overlooking staff training
SDN introduces new tools and processes. If your IT team isn’t trained, they may struggle to manage the system effectively. Invest in proper training before and after deployment.
Mistake #4: Not planning for scalability
Your SDN should grow with your business. If you don’t plan for future expansion, you may need to redesign your network sooner than expected. Choose solutions that support modular growth.
Mistake #5: Failing to test configurations
Misconfigured policies can disrupt services. Always test changes in a controlled environment before rolling them out across the network.
Mistake #6: Underestimating security needs
SDN can improve security, but only if it’s configured correctly. Use access controls, encryption, and monitoring tools to protect your network.
Key benefits of software defined networking
SDN offers several advantages that make it a smart choice for growing businesses:
- Centralized control makes it easier to manage complex networks.
- Automation reduces manual tasks and human error.
- Faster deployment of new applications and services.
- Improved network visibility and performance monitoring.
- Easier integration with cloud and virtualization platforms.
- Enhanced security through programmable policies.
How the data plane and control plane work together
In traditional networks, the control plane and data plane are built into each device. With SDN, the control plane is centralized, while the data plane remains on the physical devices. This separation allows for faster decision-making and easier updates.
The control plane decides where traffic should go, while the data plane forwards the traffic based on those decisions. This setup improves efficiency and allows for real-time adjustments to network traffic.
Key components of SDN architecture
SDN architecture includes several layers that work together to deliver flexible and scalable networking. Here's a breakdown of the main components.
Component #1: SDN controller
The controller is the central system that manages network policies and traffic flow. It communicates with both the applications and the network devices.
Component #2: Southbound APIs
These are protocols like OpenFlow that allow the controller to talk to the network devices. They forward instructions from the controller to the switches and routers.
Component #3: Northbound APIs
These allow applications to interact with the controller. They help automate tasks like load balancing, security, and traffic shaping.
Component #4: Network devices
These include switches, routers, and servers that handle the actual data forwarding. They follow the instructions given by the controller.
Component #5: Applications
Applications use northbound APIs to request network services. This could include anything from bandwidth allocation to firewall rules.
Component #6: Management tools
These tools help monitor performance, detect issues, and manage configurations across the SDN environment.
Planning a smooth SD-WAN implementation
SD-WAN is a practical use case of SDN that helps businesses manage wide area networks more efficiently. When planning an SD-WAN implementation, start by identifying your key locations and traffic patterns. This helps you choose the right topology and hardware.
Next, define your performance and security requirements. SD-WAN allows you to prioritize traffic, apply encryption, and use multiple connections for redundancy. Make sure your deployment plan includes testing, training, and ongoing support.
Best practices for managing SDN systems
To get the most from your SDN investment, follow these best practices:
- Document your network architecture and update it regularly.
- Use automation tools to reduce manual errors.
- Monitor traffic and performance in real time.
- Apply security policies consistently across all devices.
- Schedule regular audits and configuration reviews.
- Keep your controller software and APIs up to date.
How Sterling can help with software defined networking
Are you a business with 20 to 80 employees looking for a better way to manage your network? If you're growing and need more control, flexibility, and visibility, software defined networking could be the answer.
At Sterling, we help businesses design, deploy, and manage SDN solutions tailored to their needs. Our team understands the challenges of scaling IT infrastructure and can guide you through every step—from planning to SD-WAN implementation. Contact us today to see how we can support your goals.
Frequently asked questions
What is the difference between a traditional network and SDN?
Traditional networks use hardware-based control, where each router or switch makes its own decisions. In contrast, software defined networking centralizes the control plane, allowing one controller to manage the entire network. This makes it easier to automate, configure, and scale the system.
By separating the control plane from the data plane, SDN provides more flexibility and faster response times. It also simplifies network management, especially in environments with complex topology.
How does SDN improve network performance?
SDN improves performance by allowing centralized control of traffic flow. The controller can quickly adjust routes and prioritize traffic based on real-time needs. This reduces congestion and improves reliability.
It also enables automation and better use of network resources. For example, you can configure rules that forward traffic through the most efficient path, reducing latency and improving user experience.
Is SDN suitable for small to mid-sized businesses?
Yes, software defined networking can benefit small to mid-sized businesses by simplifying network management and reducing costs. It’s especially useful if you have multiple locations or remote workers.
With SDN, you can centralize control and automate tasks that would otherwise require manual setup. This makes it easier to scale your network as your business grows.
What role does the SDN controller play?
The SDN controller acts as the brain of the network. It communicates with both the applications and the network devices to manage traffic flow and enforce policies.
Using protocols like OpenFlow, the controller sends instructions to switches and routers. This allows for real-time adjustments and centralized decision-making across the network.
Can SDN work with existing hardware?
In many cases, yes. Some existing switches and routers can be updated to support SDN protocols. However, full compatibility depends on your current equipment and the SDN solution you choose.
Before deployment, assess your current infrastructure and determine what needs to be upgraded or replaced. This ensures a smooth transition and better performance.
How does SDN support virtualization and cloud services?
Software defined networking integrates well with virtualization platforms by providing dynamic network configurations. It allows virtual machines to move across servers without manual reconfiguration.
It also supports cloud services by enabling secure, automated connections between on-premises and cloud environments. This makes it easier to deploy new services and manage hybrid networks.
