Question

Use the Internet to research software defined network (SDN). How do they function? What are their features? What are the advantages of each type? What are the disadvantages? Create a table comparing SDNs with traditional networks. If you were to recommend a SDN for your school or business, what would be the reason(s)?

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Answer 1

QUESTION)

Use the Internet to research software defined network (SDN). How do they function? What are their features? What are the advantages of each type? What are the disadvantages? Create a table comparing SDNs with traditional networks. If you were to recommend a SDN for your school or business, what would be the reason(s)?

ANSWER)

1)DEFINATION OF SDN

Software-defined networking (SDN) transfers network management from the physical routers and switches to software. This gives companies the capability to separate the data plane and control plane in routers and switchers. This allows the company to have more control over their own system with less effort.

2) SDN WORKS

How SDN works

SDN encompasses several types of technologies, including functional separation, network virtualization and automation through programmability.

Originally, SDN technology focused solely on separation of the network control plane from the data plane. While the control plane makes decisions about how packets should flow through the network, the data plane actually moves packets from place to place.

In a classic SDN scenario, a packet arrives at a network switch, and rules built into the switch's proprietary firmware tell the switch where to forward the packet. These packet-handling rules are sent to the switch from the centralized controller.

The switch -- also known as a data plane device -- queries the controller for guidance as needed, and it provides the controller with information about traffic it handles. The switch sends every packet going to the same destination along the same path and treats all the packets the exact same way.

Software-defined networking uses an operation mode that is sometimes called adaptive or dynamic, in which a switch issues a route request to a controller for a packet that does not have a specific route. This process is separate from adaptive routing, which issues route requests through routers and algorithms based on the network topology, not through a controller.

The virtualization aspect of SDN comes into play through a virtual overlay, which is a logically separate network on top of the physical network. Users can implement end-to-end overlays to abstract the underlying network and segment network traffic. This microsegmentation is especially useful for service providers and operators with Multi-tenant cloud environments and cloud services, as they can provision a separate virtual network with specific policies for each tenant.

3) SDN FEATURE

A typical representation of SDN architecture comprises three layers: the application layer, the control layer and the infrastructure layer.

1)The application layer

It contains the typical network applications or functions organizations use, which can include intrusion detection systems, load balancing or firewalls. Where a traditional network would use a specialized appliance, such as a firewall or load balancer, a software-defined network replaces the appliance with an application that uses the controller to manage data plane behavior.

2)The control layer

It represents the centralized SDN controller software that acts as the brain of the software-defined network. This controller resides on a server and manages policies and the flow of traffic throughout the network.

3)The infrastructure layer

It is made up of the physical switches in the network.

These three layers communicate using respective northbound and southbound application programming interfaces (APIs). For example, applications talk to the controller through its northbound interface, while the controller and switches communicate using southbound interfaces, such as OpenFlow -- although other protocols exist.

There is currently no formal standard for the controller's northbound API to match OpenFlow as a general southbound interface. It is likely the OpenDaylight controller's northbound API may emerge as a de facto standard over time, given its broad vendor support.

4)Pros and Cons of Software-Defined Networking (SDN)

Pros

There are a number of reasons that people are changing to a SDN system at their office.

1)visibility

Separating the data plane and control plane gives the IT department an aerial-like view of the entire network. This makes changes much easier, as you can see the effects clearly.

2)increased speed

The visibility allows IT departments to makes changes that can increase the speed of the entire network.

3)better security

In many ways, SDN systems allow companies better security. The visibility helps the IT department spot any possible security breeches and stop it from spreading easily. Furthermore, the people with access to the controller can clarify secure routes in the system without a firewall to block any invalid routes.

Cons

SDN systems are still a new technology. Being a new technology, there are still areas that could use improvement.

1)vulnerability of the controller

The controller is the way that the IT department will manage the network instead of the routers and switches. This means that the controller must be completely secure. Many soft-ware defined networks can track who and when people make changes, but companies must carefully monitor who has access to the controller and keep access secure.  

2)distributed denial-of-service attacks

If a large number of undeclared routes are brought into the network at the same time, they will request a specific route. Unfortunately, this influx in requests can make it difficult for the network to respond to actual requests. The system would then find itself unable to delegate new routes, causing a headache for the IT department.

3)lack of hardware security

One of the disadvantages of a SDN network is that since you are eliminating use of the physical routers and switches, you won't have the security that comes with them. The main one that you will be missing is the firewall. This can leave your network more vulnerable if you're not careful. Contact an IT management service for more help.

5) SDN VS TRADITIONAL NETWORKING

SDN	TRADITIONAL NETWORKING
1)SDN is software-based.	1)traditional networking is usually hardware-based
2)it is software-based, SDN is more flexible, allowing users greater control and ease for managing resources virtually throughout the control plane.	2)Inversely, traditional networks use switches, routers and other physical infrastructure to create connections and run the network.
3)Virtualization epitomizes the primary difference between SDN and traditional networking. When SDN virtualizes your entire network, it generates an abstract copy of your physical network, and lets you provision resources from a centralized location.	3) a traditional network the physical location of the control plane hinders an IT administrator’s ability to control the traffic flow.

6)SDN FOR SCHOOL WITH REASON.

1)Software can help education by reducing IT acquisition costs over time. New features get rolled out with every new software version, which increases hardware longevity,

2)SDN offers programmability, which provides extensibility, and orchestration, which helps avoid human error.

3)While current networks barely use Quality of Service (QoS), schools can use SDN to apply QoS policies automatically and ensure bandwidth requirements are met,That way, schools can avoid a situation in which administrators can't get their work done because all bandwidth is reserved for student testing.

4)Meanwhile, universities can apply QoS protection mechanisms to the edge to control and secure bandwidth usage in dorms, where it's a Wild West of devices and applications.