What is software-defined networking (SDN)?
SDN is a networking paradigm that relies on software-based controllers or application programming interfaces (APIs) to communicate with the underlying hardware infrastructure and direct network traffic.
This architecture is in contrast to traditional networks, which regulate network traffic via specialized hardware devices (i.e., routers and switches). Through software, SDN can establish and govern a virtual network — or traditional hardware.
While network virtualization enables organizations to create multiple virtual networks within a single physical network or connect devices on different physical networks to create a single virtual network, software-defined networking introduces a new method of controlling data packet routing through a centralized server.
Why is software-defined networking necessary?
SDN is a significant advancement over traditional networking in that it permits the following:
Increased control with increased speed and flexibility: Rather than manually programming various vendor-specific hardware devices, developers may program one open standard software-based controller to regulate traffic flow across a network. Additionally, network managers have more choice in terms of networking equipment, as they can use a single protocol to communicate with an unlimited number of hardware devices via a central controller.
Customizable network infrastructure: Admins can adjust network services and adapt the network architecture in real-time by configuring network services and resources from a single location using software-defined networking. This enables network administrators to optimize data flow via the network and prioritize critical applications.
Robust security: A software-defined network provides visibility across the entire network, providing a more holistic picture of security concerns. With the rise of internet-connected smart devices, SDN outperforms traditional networking. Operators can build distinct zones for devices that require varying levels of protection or quarantine compromised devices immediately to prevent them from infecting the rest of the network.
The primary distinction between SDN and conventional networking is in the infrastructure: SDN is a software-defined networking technology, whereas traditional networking is hardware-based. SDN is far more versatile than traditional networking due to the software-based control plane. Providing administrators with centralized management over the network and the ability to change the configuration settings, provision resources, and enhance network capacity is made possible by the user interface.
Additionally, there are security distinctions between SDN and traditional networking. SDN improves security in various ways due to increased visibility and the ability to build safe paths. However, because software-defined networks rely on a centralized controller, it is critical to secure the controller to maintain a secure network.
How does software-defined networking (SDN) work?
Here are the fundamentals of SDN: SDN (as with anything virtualized) separates the software from the hardware. SDN separates the control plane, which selects where to transmit traffic, from the data plane, which forwards the traffic. This enables network managers who leverage software-defined networking to program and manage the entire network through a single pane of glass rather than device by device.
A basic SDN architecture is composed of three components, each of which may be physically situated in a separate physical location:
- Applications that exchange requests for resources or information about the network in general
- Controllers which make routing decisions based on information from applications.
- Networking devices that get instructions from the controller regarding the data’s routing.
Physical or virtual networking devices are responsible for transporting data over the network. Virtual switches, which can be integrated into either software or hardware, can sometimes take over the tasks of physical switches and combine their functions into a single, intelligent switch. The switch verifies the data packets’ integrity as well as their virtual machine destinations before forwarding them.
Software-Defined Networking’s Advantages (SDN)
Many of today’s services and applications, particularly those using the cloud, would be impossible to run without SDN. SDN enables the effortless movement of data between remote sites, which is crucial for cloud applications.
Additionally, SDN enables the rapid movement of workloads across a network. For example, by segmenting a virtual network using network functions virtualization (NFV), telecoms companies can shift client services to lower-cost servers or even to the customer’s servers. Service providers can leverage a virtual network infrastructure to migrate workloads between private and public cloud infrastructures as needed and rapidly launch new client services. Additionally, SDN enables any network to flex and expand more easily as network administrators add or remove virtual computers, whether on-premises or in the cloud.
Finally, SDN’s speed and flexibility enable it to accommodate upcoming trends and technologies like edge computing and the Internet of Things, both requiring data to be transferred quickly and easily between remote sites.
What distinguishes SDN from traditional networking?
The primary distinction between SDN and conventional networking is in the infrastructure: SDN is a software-defined networking technology, whereas traditional networking is hardware-based. SDN is far more versatile than traditional networking due to the software-based control plane. It enables administrative authorities to monitor the network, modify configuration settings and provide resources and expand network capacity—all without installing additional hardware via a centralized user interface.
Additionally, there are security distinctions between SDN and traditional networking. SDN improves security in various ways due to increased visibility and the ability to build safe paths. However, because software-defined networks rely on a centralized controller, securing the controller is critical for network security, and this single point of failure provides a possible weakness for SDN.
What are the various SDN models?
While all software-defined networking is based on the concept of centralized software managing the flow of data in switches and routers, there are several SDN architectures.
Open SDN: Network managers utilize a protocol such as OpenFlow to manage the data plane behavior of virtual and physical switches.
SDN by APIs: Rather than relying on an open protocol, application programming interfaces (APIs) govern how data flows through the network on each device.
Another type of software-defined networking is the SDN Overlay Model, which operates a virtual network on top of existing hardware architecture, creating dynamic tunnels to on-premises and faraway data centers. The virtual network distributes bandwidth across multiple channels and assigns devices to each channel, completely bypassing the actual network.
Hybrid SDN: This approach mixes software-defined networking with legacy networking protocols in a single environment to serve many network functions. Standard networking protocols continue to direct some traffic, while SDN assumes responsibility for the rest, allowing network administrators to phase in SDN into an existing system.
You will have an overall understanding of Software-Defined Networking through this article. SPOTO educational resources, including 100% authentic Cisco exam dumps covering CCNA, CCNP, and CCIE exam questions, help interested IT professionals improve their understanding of SDN and develop skills in these critical topic areas.