Module 8: Quiz

Question 1

An OpenFlow switch can function as a router.

T/F

Answer 1

True

OpenFlow switches have capabilities that allow them to perform routing functions.

Question 2

Which plane executes a network policy?

Answer 2

Data Plane

The Data Plane is responsible for the actual forwarding of packets based on the policies defined.

Question 3

Which type of network can implement load balancing?
* Conventional Networks
* Software-Defined Networks
* Neither conventional nor software-defined networks
* Both conventional and software defined networks

Answer 3

• Both conventional and software defined networks

Both types of networks can utilize load balancing techniques.

Question 4

Which type of network decouples the control and data planes?

Answer 4

Software-Defined Networks

SDNs separate the control logic from the forwarding hardware.

Question 5

Middleboxes can only be used in conventional networks.

T/F

Answer 5

False

Middleboxes can also be utilized in Software-Defined Networks.

Question 6

Which of the following can be implemented as a network application in software-defined networking?
* Routing
* Security enforcement
* Quality of Service (QoS) enforcement
* All of the above

Answer 6

All of the above

SDN allows for various applications to be implemented for network management.

Question 7

The networking operating system (NOS) is a part of the data plane.

T/F

Answer 7

False

The NOS typically operates in the control plane.

Question 8

The physical devices in an SDN network have embedded intelligence and control required to perform forwarding tasks.

T/F

Answer 8

False

Question 9

When a packet arrives in an OpenFlow device and it does not match any of the rules in one of the tables, that packet is always dropped.

T/F

Answer 9

False

The packet may be sent to the controller for further processing instead of being dropped.

Question 10

The Southbound interfaces are the separating medium between the Network-control Applications and the Control plane functionality.

T/F

Answer 10

False

Question 11

OpenFlow enables the communication between the control plane and data plane through event-based messages, flow statistics and packet messages that are sent from forwarding devices to controller.

T/F

Answer 11

True

This communication is essential for effective network management.

Question 12

One of the disadvantages of an SDN centralized controller architecture is that it can introduce a single point of failure and also scaling issues.

T/F

Answer 12

True

Centralized architectures can be vulnerable to failures affecting the entire network.

Question 13

A distributed controller can be a centralized cluster of nodes or a physically distributed set of elements.

T/F

Answer 13

True

This flexibility allows for improved resilience and scalability.

Question 14

A distributed controller can only be used in large networks.

T/F

Answer 14

False

Distributed controllers can be beneficial in networks of various sizes.

Question 15

ONOS is an example of a centralized controller platform.

T/F

Answer 15

False

ONOS is designed to be a distributed controller platform.

Question 16

In order to make forwarding and policy decisions in ONOS, applications get information from the view and then update these decisions back to the view.

T/F

Answer 16

True

This process allows ONOS to maintain an accurate and updated network state.

Question 17

In order to achieve fault tolerance, whenever there is a failure of an ONOS instance, a master is chosen randomly for each of the switches that were controlled by the failed instance.

T/F

Answer 17

False

Question 18

The purpose of the creation of the P4 language was to offer programmability on the control plane.

T/F

Answer 18

False

P4 is designed to provide programmability for packet processing in the data plane.

Question 19

P4 acts as an interface between the switches and the controller, and its main goal is to allow the controller to define how the switches operate.

T/F

Answer 19

True

This interface is crucial for customizing switch behavior.

Question 20

The P4 model allows the design of a common language to write packet processing programs that are independent of the underlying devices.

T/F

Answer 20

True

This independence enhances flexibility in network programming.

Question 21

In an SDX architecture, each AS can define forwarding policies as if it is the only participant at the SDX, as well as having its own SDN applications for dropping, modifying or forwarding their traffic.

T/F

Answer 21

True

This autonomy allows for tailored traffic management within the SDX.