Software-defined networking (SDN) is a method of networking that leverages software-based controllers or application programming interfaces (APIs) to oversee traffic on the network and communicate with the core hardware infrastructure.

This differs from legacy networks which use dedicated hardware assets (routers and switches) to monitor network traffic. SDN can generate and control a virtual network or control a traditional hardware network with software that automates and regulates the provisioning and management of network resources.

While network virtualization provides the ability to divide virtual networks in a physical network or connect devices on multiple physical networks within a single virtual network, software-defined networking facilitates a novel way to control the routing of data packets through a centralized server.

Importance of Attack Surface and Threat Intelligence

How Does Software-Defined Networking (SDN) Work?

In an SDN, the software is decoupled from the hardware. SDN then separates the two network device planes, shifting the control plane which decides where to send traffic to software, and leaving behind the data plane that accelerates the traffic in the hardware. This allows network administrators to control the network intelligently and centrally using software applications or programs to manage the entire network consistently and holistically rather than a device-by-device basis.

SDN Architecture

Applications connect resource requests or information about the network. Controllers use the information from these applications to decide how to route a data packet. Networking devices then collect information from the controller and decipher where to move the data.

These three elements can often be located in different physical spaces.

Physical or virtual networking devices move data across the network. In some cases, virtual switches may be entrenched in either the software or the hardware, can take over the duties of physical switches and merge their tasks into a single intelligent switch. The switch then verifies the reliability of both the data stacks and their virtual machine destinations and pushes the packets along.

Benefits of Software-Defined Networking (SDN)

SDN provides a range of benefits over legacy networking that includes:

Enhanced Control with Better Speed and Flexibility: Rather than manually programming multiple vendor-specific hardware tools, SDN allows monitoring the flow of traffic over a network easily by programming an open standard software-based controller. Networking administrators also have more options when choosing networking devices as they can choose an open-source code to communicate with any number of hardware tools through a central controller.

Customizable Network Infrastructure: With software-defined networking, administrators can design network services and allot virtual resources to change the network infrastructure in real-time through one central location. This allows network admins to augment the flow of data through the network, focusing on applications that require more availability.

Robust Security: A software-defined network enables visibility into the entire network, providing a better view of security threats. With the spread of smart devices that connect to the internet, SDN offers clear advantages over legacy networking solutions. Developers can create distinct zones for devices that need different levels of security, or instantly quarantine infected devices so they cannot compromise the rest of the network and devices.

How is SDN Different From Traditional Networking?

The biggest difference between SDN and legacy networking is infrastructure. SDN is software-enabled, whereas legacy networking is hardware-based. Because SDN’s are software based, the control panel is much more flexible than traditional/legacy networking. It allows admins monitor the network, alter configuration settings, deliver resources, and enhance network capacity—all from a unified user interface, without adding additional hardware.

There are also security disparities between SDN and traditional networking. Thanks to greater adoption rates and the ability to describe secure pathways, SDN offers improved security in several ways. However, as software-defined networks use a central controller, securing the controller is key to maintaining a secure network and this single point of failure characterizes a potential vulnerability of SDN.

What are The Different Models of SDN?

While the practice of a centralized software controlling the flow of data in switches and routers applies to all software-defined networking, there are different models of SDN, as defined below:

Open SDN: Network administrators employ a protocol like OpenFlow to regulate the performance of virtual and physical switches at the data plane level.

SDN by APIs: Rather than utilizing an open protocol, application programming interfaces regulate how data travels through the network on each device.

SDN Overlay Model: This is another type of software-defined networking which operates a virtual network on top of active hardware infrastructure, creating dynamic tunnels to various on-premise and remote data centers. The virtual network assigns bandwidth over an array of channels and allocates devices to each channel, leaving the physical network untouched.

Hybrid SDN: This model unites software-defined networking with traditional/legacy networking practices in one environment to support diverse functions on a network. Standard networking protocols continue to direct traffic, while SDN takes up onus for other traffic, letting network administrators to create SDN in stages to a legacy environment.

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SDN Architecture

Introduction to Software Defined Networks (SDN) and its relevance in the DC


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