1. What is Software Defined Networking (SDN)? An architecture that
decouples the network control plane from the data plane, enabling centralized
network management and programmability through software applications.
2. What are the three layers of SDN architecture? The Application Layer,
Control Layer, and Infrastructure Layer (Data Plane).
3. What is the control plane in networking? The part of the network that
determines how packets should be forwarded, making routing decisions and
managing network topology.
4. What is the data plane in networking? The part of the network responsible
for actual packet forwarding based on decisions made by the control plane.
5. What is the management plane? The network layer responsible for
monitoring and configuring network devices, separate from control and data
planes.
6. What is OpenFlow? A communications protocol that enables the control
plane to interact with the forwarding plane in SDN architectures.
7. What is a southbound interface in SDN? The interface between the control
layer and the infrastructure layer, typically using protocols like OpenFlow.
8. What is a northbound interface in SDN? The interface between the control
layer and the application layer, providing APIs for applications to communicate
with the controller.
9. What is an SDN controller? The centralized control point in an SDN
architecture that manages flow control, network policies, and communicates
with network devices.
10. What is network programmability? The ability to configure, manage, and
optimize network behavior through software applications rather than manual
configuration.
11. What is a flow in SDN terminology? A sequence of packets matching a
specific set of criteria, treated as a single unit for forwarding purposes.
,12. What is a flow table? A data structure in SDN switches that contains flow
entries defining how packets should be processed and forwarded.
13. What are the main benefits of SDN? Centralized management, network
programmability, automation, improved agility, reduced operational costs, and
simplified network design.
14. What is network virtualization? The process of creating multiple virtual
networks on top of a single physical network infrastructure.
15. What is the difference between SDN and traditional networking?
Traditional networking has control and data planes tightly coupled in each
device, while SDN separates them with centralized control.
16. What is an OpenFlow switch? A network device that forwards packets
based on flow tables populated by an OpenFlow controller.
17. What is match-action in OpenFlow? The process where packets are
matched against flow table entries and actions are applied based on the match.
18. What are the main components of a flow entry? Match fields, priority,
counters, instructions/actions, timeouts, and cookie.
19. What is packet-in message in OpenFlow? A message sent from a switch
to the controller when a packet doesn't match any flow entry or when explicitly
configured.
20. What is packet-out message in OpenFlow? A message sent from the
controller to a switch instructing it to forward a specific packet out of specified
ports.
21. What is a flow-mod message? A message from the controller to modify the
flow table in an OpenFlow switch.
22. What are common SDN controllers? OpenDaylight, ONOS, Ryu,
Floodlight, POX, and Cisco ACI.
23. What is OpenDaylight? An open-source SDN controller platform that
provides a modular, pluggable architecture for building SDN solutions.
24. What is ONOS? Open Network Operating System, a carrier-grade SDN
controller designed for high availability and scalability.
25. What is the purpose of a network operating system in SDN? To provide
a centralized view of the network and APIs for applications to interact with
network infrastructure.
, 26. What is network abstraction in SDN? Hiding the complexity of
underlying network hardware and providing simplified interfaces for network
management.
27. What is intent-based networking? A higher-level approach where
administrators specify what they want the network to accomplish rather than
how to accomplish it.
28. What is overlay networking? Creating virtual networks on top of an
existing physical network infrastructure using tunneling technologies.
29. What is underlay networking? The physical network infrastructure that
provides connectivity for overlay networks.
30. What is VXLAN? Virtual Extensible LAN, a tunneling protocol that
encapsulates Layer 2 frames in Layer 4 UDP packets for network virtualization.
31. What is the purpose of VXLAN? To overcome VLAN limitations, support
multi-tenancy, and enable Layer 2 connectivity across Layer 3 networks.
32. What is a VTEP? VXLAN Tunnel Endpoint, a device that encapsulates
and de-encapsulates VXLAN traffic.
33. What is GRE? Generic Routing Encapsulation, a tunneling protocol that
can encapsulate various network layer protocols.
34. What is STT? Stateless Transport Tunneling, a tunneling protocol designed
for network virtualization in data centers.
35. What is NFV? Network Functions Virtualization, the concept of replacing
dedicated network appliances with software running on commodity hardware.
36. How does NFV relate to SDN? NFV focuses on virtualizing network
functions, while SDN focuses on network control; they complement each other
but are distinct.
37. What is a Virtual Network Function (VNF)? A software implementation
of a network function that can run on virtualized infrastructure.
38. What is network slicing? Creating multiple logical networks with different
characteristics on a shared physical infrastructure.
39. What is Quality of Service (QoS) in SDN? Mechanisms to prioritize
certain types of traffic and guarantee specific performance levels.
40. What is network topology discovery in SDN? The controller's ability to
automatically discover and map network devices and their connections.
decouples the network control plane from the data plane, enabling centralized
network management and programmability through software applications.
2. What are the three layers of SDN architecture? The Application Layer,
Control Layer, and Infrastructure Layer (Data Plane).
3. What is the control plane in networking? The part of the network that
determines how packets should be forwarded, making routing decisions and
managing network topology.
4. What is the data plane in networking? The part of the network responsible
for actual packet forwarding based on decisions made by the control plane.
5. What is the management plane? The network layer responsible for
monitoring and configuring network devices, separate from control and data
planes.
6. What is OpenFlow? A communications protocol that enables the control
plane to interact with the forwarding plane in SDN architectures.
7. What is a southbound interface in SDN? The interface between the control
layer and the infrastructure layer, typically using protocols like OpenFlow.
8. What is a northbound interface in SDN? The interface between the control
layer and the application layer, providing APIs for applications to communicate
with the controller.
9. What is an SDN controller? The centralized control point in an SDN
architecture that manages flow control, network policies, and communicates
with network devices.
10. What is network programmability? The ability to configure, manage, and
optimize network behavior through software applications rather than manual
configuration.
11. What is a flow in SDN terminology? A sequence of packets matching a
specific set of criteria, treated as a single unit for forwarding purposes.
,12. What is a flow table? A data structure in SDN switches that contains flow
entries defining how packets should be processed and forwarded.
13. What are the main benefits of SDN? Centralized management, network
programmability, automation, improved agility, reduced operational costs, and
simplified network design.
14. What is network virtualization? The process of creating multiple virtual
networks on top of a single physical network infrastructure.
15. What is the difference between SDN and traditional networking?
Traditional networking has control and data planes tightly coupled in each
device, while SDN separates them with centralized control.
16. What is an OpenFlow switch? A network device that forwards packets
based on flow tables populated by an OpenFlow controller.
17. What is match-action in OpenFlow? The process where packets are
matched against flow table entries and actions are applied based on the match.
18. What are the main components of a flow entry? Match fields, priority,
counters, instructions/actions, timeouts, and cookie.
19. What is packet-in message in OpenFlow? A message sent from a switch
to the controller when a packet doesn't match any flow entry or when explicitly
configured.
20. What is packet-out message in OpenFlow? A message sent from the
controller to a switch instructing it to forward a specific packet out of specified
ports.
21. What is a flow-mod message? A message from the controller to modify the
flow table in an OpenFlow switch.
22. What are common SDN controllers? OpenDaylight, ONOS, Ryu,
Floodlight, POX, and Cisco ACI.
23. What is OpenDaylight? An open-source SDN controller platform that
provides a modular, pluggable architecture for building SDN solutions.
24. What is ONOS? Open Network Operating System, a carrier-grade SDN
controller designed for high availability and scalability.
25. What is the purpose of a network operating system in SDN? To provide
a centralized view of the network and APIs for applications to interact with
network infrastructure.
, 26. What is network abstraction in SDN? Hiding the complexity of
underlying network hardware and providing simplified interfaces for network
management.
27. What is intent-based networking? A higher-level approach where
administrators specify what they want the network to accomplish rather than
how to accomplish it.
28. What is overlay networking? Creating virtual networks on top of an
existing physical network infrastructure using tunneling technologies.
29. What is underlay networking? The physical network infrastructure that
provides connectivity for overlay networks.
30. What is VXLAN? Virtual Extensible LAN, a tunneling protocol that
encapsulates Layer 2 frames in Layer 4 UDP packets for network virtualization.
31. What is the purpose of VXLAN? To overcome VLAN limitations, support
multi-tenancy, and enable Layer 2 connectivity across Layer 3 networks.
32. What is a VTEP? VXLAN Tunnel Endpoint, a device that encapsulates
and de-encapsulates VXLAN traffic.
33. What is GRE? Generic Routing Encapsulation, a tunneling protocol that
can encapsulate various network layer protocols.
34. What is STT? Stateless Transport Tunneling, a tunneling protocol designed
for network virtualization in data centers.
35. What is NFV? Network Functions Virtualization, the concept of replacing
dedicated network appliances with software running on commodity hardware.
36. How does NFV relate to SDN? NFV focuses on virtualizing network
functions, while SDN focuses on network control; they complement each other
but are distinct.
37. What is a Virtual Network Function (VNF)? A software implementation
of a network function that can run on virtualized infrastructure.
38. What is network slicing? Creating multiple logical networks with different
characteristics on a shared physical infrastructure.
39. What is Quality of Service (QoS) in SDN? Mechanisms to prioritize
certain types of traffic and guarantee specific performance levels.
40. What is network topology discovery in SDN? The controller's ability to
automatically discover and map network devices and their connections.
