13.6.3 Module Quiz – Network Virtualization (Answers)

Explanation: Curriculum Reference: Module 7.2
This item is based on information contained in the presentation.
There is no such thing as BaaS. Infrastructure as a service (IaaS) is when key network devices such as routers and firewalls are leased from a provider. Wireless as a service (WaaS) is when a provider provides wireless connectivity at a fixed monthly cost.

Explanation: With server virtualization, traffic in a data center contains a considerable amount of data exchanges between virtual servers (referred to as East-West traffic). For the client-server model, the traffic pattern between virtual servers and clients will not change. From a routing perspective, client requests to a virtual server will still be routed to that server.

Explanation: An infrastructure device contains the control plane and data plane. The control plane contains Layer 2 and Layer 3 route forwarding mechanisms that construct loop-free paths within a network. The data plane of each device is used to forward traffic flows.

Explanation: OpenFlow was developed at Stanford University to manage traffic between routers, switches, and wireless access points and a controller. It is the original and widely implemented southbound API for SDN.​ OpenStack is a virtualization and orchestration platform available to build scalable cloud environments and provide an infrastructure as a service (IaaS) solution. It is often used with Cisco ACI. IEEE 802.1aq is a replacement to the Spanning Tree Protocol (STP) that allows all paths to be active with multiple equal cost paths.​ Interface to the Routing System uses a fast path protocol to populate the network device routing table.​

Explanation: The Cisco ACI architecture contains three core components:
– Application Network Profile (ANP) – An ANP is a collection of end-point groups (EPG), their connections, and the policies that define those connections.
– Application Policy Infrastructure Controller (APIC) – APIC is a centralized software controller that manages and operates a scalable ACI clustered fabric.
– Cisco Nexus 9000 Series switches – Provides an application-aware switching fabric and works with an APIC to manage the virtual and physical network infrastructure.
OpenFlow enabled switches are required in SDN implementation. Both Interface to the Routing System (I2RS) and Transparent Interconnection of Lots of Links (TRILL) are different approaches developed for network virtualization.

Explanation: Infrastructure as a service (IaaS) provides an environment where users have an on-demand infrastructure that they can install any platform as needed.

Explanation: Large enterprises typically have their own data center to manage data storage and data processing needs. The data center can be used to serve internal IT needs. In other words, the data center becomes a private cloud, a cloud computing infrastructure just for internal services.

Explanation: A cloud solution is used for many reasons, but some of the common services and reasons to use a cloud-based solution are as follows:
– access to corporate data through the Internet
– outsourced services
– housing for IT equipment, maintenance, and management
– reduced costs for equipment, electricity, disaster prevention, physical plant (room, cabling, air conditioning, water cooling, etc.), and personnel

Explanation: In SDN architecture, each data flow through the network must first get permission from the SDN controller. If the controller allows a flow, it computes a route for the flow to take and adds an entry for that flow in each of the switches along the path. Communication between the controller and the switches typically uses an open standard protocol and an API, such as OpenFlow.

Explanation: Abstraction layers help describe network protocols within the architecture of a computer system. Each layer uses programming code to interface with the layers above and below. The following abstraction layers make up a computer system:
– Hardware
– Firmware
– Assembler
– Kernel
– OS
– Services

Explanation: In network virtualization, the control plane function of each network device is removed and is performed by a centralized controller. The controller then can communicate control plane functions to each of the network devices. This allows the network devices to focus all resources on forwarding plane functions.

Explanation: With server virtualization, the data exchanges between virtual servers in a data center is referred to as East-West traffic.

Explanation: In network virtualization design, the control plane function is removed from each network device and is performed by a centralized controller. The centralized controller communicates control plane functions to each network device and each device focuses on forwarding data.

Explanation: Platform as a service (PaaS) provides a collaborative environment where multiple developers can create software and host an application through a Cloud provider.

Explanation: The Internet of Things (IoT) is a phrase that denotes the billions of electronic devices that are now able to connect to data networks and the internet.

Explanation: With IaaS, the cloud provider is responsible for access to the network equipment, virtualized network services, and supporting network infrastructure.

Explanation: Cloud computing enables access to organizational data anywhere and at any time; streamlines the organization’s IT operations by subscribing only the needed services; eliminates or reduces the need for onsite IT equipment, maintenance, and management; reduces costs for equipment, energy, physical plant requirements, and personnel training needs; and enables rapid responses to increasing data volume requirements.

Explanation: A private cloud’s applications and services are intended for a specific organization or entity, such as the government.

Explanation: A benefit of virtualization is increased server uptime with advanced redundant fault-tolerance features such as live migration, storage migration, high availability, and distributed resource scheduling.

Explanation: The terms cloud computing and virtualization are often used interchangeably; however, they mean different things. Virtualization is the foundation of cloud computing. Without it, cloud computing, as it is most widely implemented, would not be possible. Cloud computing separates the application from the hardware. Virtualization separates the OS from the hardware.

Explanation: A Type 2 hypervisor, also called a hosted hypervisor, is software that creates and runs VM instances. A big advantage of Type 2 hypervisors is that management console software is not required.

Explanation: A Type 1 hypervisor is installed directly on the server or networking hardware. Instances of an OS are installed on the hypervisor. Type 1 hypervisors have direct access to the hardware resources; therefore, they are more efficient than hosted architectures. Type 1 hypervisors improve scalability, performance, and robustness.

Explanation: Software-defined networking (SDN) is a network architecture that has been developed to virtualize the network. For example, SDN can virtualize the control plane. It is also known as controller-based SDN. SDN moves the control plane from each network device to a central network intelligence and policy-making entity called the SDN controller.

Explanation: The control plane contains Layer 2 and Layer 3 route forwarding mechanisms, such as routing protocol neighbor tables and topology tables, IPv4 and IPv6 routing tables, STP, and the ARP table. Information sent to the control plane is processed by the CPU.

Explanation: Using Type 1 hypervisors is also called the “bare metal” approach because the hypervisor is installed directly on the hardware. Type 1 hypervisors are usually used on enterprise servers and data center networking devices.

Explanation: Type 2 hypervisors are very popular with consumers and with organizations experimenting with virtualization. Common Type 2 hypervisors include Virtual PC, VMware Workstation, Oracle VM VirtualBox, VMware Fusion, and Mac OS X Parallels.

Explanation: The APIC is considered to be the brains of the ACI architecture. An APIC is a centralized software controller that manages and operates a scalable ACI clustered fabric. It is designed for programmability and centralized management. It translates application policies into network programming.