6.3 Controller-Based Software Defined Architecture Flashcards
Summarize controller-based, software defined architecture (overlay, underlay, and fabric). (19 cards)
What is the control plane in a software-defined network (SDN)?
It’s responsible for making decisions about where traffic should be sent.
It determines routing, policy enforcement, and overall network behavior, typically managed by a centralized controller in SDN.
What is the data plane in SDN?
It forwards traffic based on the control plane’s decisions.
The data plane executes forwarding decisions, such as routing packets and switching data, based on instructions from the control plane.
True or False:
The control plane in SDN is decentralized.
False
SDN centralizes the control plane in a controller, which simplifies network management and policy enforcement.
Define:
overlay network
A virtual network built on top of an existing physical network.
In SDN, overlay networks abstract the physical infrastructure, enabling flexible virtualized connections between devices without modifying the underlying hardware.
Define:
underlay network
The physical network infrastructure that supports the overlay network.
The underlay provides the foundation for SDN by providing physical connections and handling packet forwarding at the hardware level.
Describe the role of a fabric in SDN architecture.
It connects the overlay and underlay for communication.
The fabric allows the controller to manage both the overlay and underlay to ensure seamless communication across all devices in the SDN.
Why are Northbound APIs important in SDN?
They enable applications to interact with the network for automation.
They provide an interface between the SDN controller and applications, allowing dynamic adjustments and resource management by enabling the exchange of network-level data.
How do Southbound APIs facilitate network management in SDN?
It lets the SDN controller send commands to network devices.
They enable control over device configurations, ensuring that the data plane forwards traffic based on the control plane’s decisions. Protocols like OpenFlow are commonly used for this purpose.
What is the main difference between overlay and underlay networks?
Overlay networks are virtual, while underlay networks are the physical infrastructure.
The overlay is managed through SDN controllers, and it allows network abstraction, while the underlay is responsible for physical packet forwarding.
. True or False:
In SDN, network devices have full control over traffic management.
False
In SDN, the control is centralized in the SDN controller, and devices only execute traffic forwarding based on instructions from the controller.
How does SDN benefit large-scale networks?
It simplifies management and makes scaling easier.
By centralizing control, SDN allows for easy integration of new devices and services, automates traffic flow, and reduces manual configuration as network demands increase.
How do SDN controllers use telemetry data?
To monitor performance and optimize traffic flow.
Telemetry data helps detect anomalies and enables informed decision-making to improve network reliability, ensuring efficient traffic management and real-time adjustments.
Define:
Intent-Based Networking (IBN)
A method where network administrators define the desired outcomes.
Intent-Based Networking allows administrators to specify high-level outcomes, which the SDN controller then translates into network configurations and policies to achieve those goals.
True or False:
SDN networks rely on individual device configuration for traffic management.
False
SDN centralizes control in the controller, which configures devices across the network, eliminating the need for individual device management.
What is a key advantage of using an overlay network?
It creates virtual networks independent of physical infrastructure.
This flexibility allows for scalable network configurations and reduces dependence on hardware changes, enhancing network adaptability.
True or False:
Overlay networks in SDN are dependent on the physical infrastructure.
False
Overlay networks are virtualized and can operate independently of the underlying physical infrastructure, providing flexibility and ease of management.
Define:
OpenFlow
A Southbound API used to communicate between the SDN controller and network devices.
OpenFlow allows the controller to configure how traffic is forwarded on devices, enabling centralized control over packet routing and switching.
True or False:
Southbound APIs in SDN allow devices to communicate directly with applications.
False
Southbound APIs like OpenFlow enable communication between the controller and network devices, not directly with applications. Applications communicate with the controller through Northbound APIs.
What is the role of virtualization in SDN?
It enables the creation of virtual network functions (VNFs).
VNFs can be dynamically deployed and managed, offering flexibility and scalability in network services, which enhances network adaptability and resource optimization.
