Module 13: Network Virtualization Flashcards
What is cloud computing?
Cloud computing involves large numbers of computers connected through a network, allowing resources and services to be accessed from anywhere.
How does cloud computing reduce operational costs?
By using resources more efficiently, eliminating or reducing the need for onsite IT equipment, and lowering energy, maintenance, and personnel costs.
What are some benefits of cloud computing for data management?
- Enables access to organizational data anywhere and anytime.
- Streamlines IT operations by subscribing only to needed services.
- Eliminates or reduces onsite IT equipment and maintenance.
- Reduces cost for equipment, energy, and personnel training.
- Enables rapid responses to increasing data volume requirements.
What are the three main cloud computing service models defined by NIST?
- Software as a Service (SaaS)
- Platform as a Service (PaaS)
- Infrastructure as a Service (IaaS)
What is Software as a Service (SaaS)?
A cloud service where the provider is responsible for access to applications and services delivered over the internet (e.g., email, communication, Office 365).
What is Platform as a Service (PaaS)?
A cloud service where the provider gives access to development tools and services used to create and deliver applications.
What is Infrastructure as a Service (IaaS)?
A cloud service where the provider gives IT managers access to network equipment, virtualized network services, and supporting infrastructure.
What are the four types of cloud computing deployment models?
- Public Cloud
- Private Cloud
- Hybrid Cloud
- Community Cloud
What is a public cloud?
A cloud where applications and services are made available to the general public.
What is a private cloud?
A cloud that is dedicated to a specific organization or entity (e.g., government, corporations).
What is a hybrid cloud?
A cloud that combines two or more cloud types (e.g., part private, part public) while remaining connected via a unified architecture.
What is a community cloud?
A cloud created for exclusive use by a specific community with shared needs (e.g., education, healthcare organizations).
What is the difference between virtualization and cloud computing?
Virtualization is the foundation of cloud computing. Virtualization separates the operating system from the hardware, whereas cloud computing delivers services over the internet using virtualized infrastructure.
What are some benefits of virtualization?
- Reduces hardware costs by requiring less physical equipment
- Lowers energy consumption and space requirements
- Increases server uptime and availability
- Improves disaster recovery
- Allows faster server provisioning and easier prototyping
- Provides legacy support for older systems
What is a “single point of failure” in traditional servers?
If a dedicated server fails, the service it provides becomes unavailable, creating a single point of failure.
What is server sprawl, and how does virtualization help?
Server sprawl occurs when dedicated physical servers remain idle, wasting energy and resources. Virtualization consolidates workloads, making more efficient use of resources.
What are the four abstraction layers in a computer system?
- Services
- Operating system
- Firmware
- Hardware
What is a Type 1 hypervisor?
A Type 1 hypervisor is installed directly on the server or networking hardware, eliminating the need for an underlying operating system (bare-metal hypervisor).
What is a Type 2 hypervisor?
A Type 2 hypervisor is software that runs on top of an existing OS and creates virtual machine (VM) instances.
What are some examples of Type 1 and Type 2 hypervisors?
- Type 1 Hypervisors (Bare-Metal): VMware ESXi, Microsoft Hyper-V, KVM
- Type 2 Hypervisors (Hosted): Oracle VirtualBox, VMware Workstation, Parallels.
Note: Hyper-V is always type 1. Even if you install it on a workstation PC - the workstation OS is made a ‘parent partition’ and a hypervisor layer is inserted between the hardware and this OS.
What is Software-Defined Networking (SDN)?
SDN is a network architecture that allows network devices to be remotely programmed via software, separating the control plane from the data plane.
What is Cisco’s version of SDN?
Cisco Application Centric Infrastructure (ACI)
What components may be included in an SDN architecture?
OpenFlow, OpenStack, SDN controllers, and network automation tools.
What is the function of an SDN controller?
The SDN controller is a logical entity that enables network administrators to manage and dictate how the data plane of switches and routers should handle network traffic.
What is the difference between the control plane and the data plane?
- Control Plane – The “brains” of the device, responsible for making forwarding decisions (e.g., routing tables, STP, ARP).
- Data Plane – The “muscle” of the device, responsible for forwarding actual traffic between ports, typically handled by specialized hardware.
What is the management plane?
The management plane is responsible for remotely configuring, managing, and monitoring network devices.
What types of information are processed in the control plane?
- Routing protocol neighbor tables
- IPv4/IPv6 routing tables
- STP (Spanning Tree Protocol)
- ARP table
What is the primary function of the data plane?
To forward network traffic based on decisions made by the control plane.
How does Cisco Express Forwarding (CEF) improve performance?
CEF allows packet forwarding to occur at the data plane without consulting the control plane, improving efficiency.
How does SDN differ from traditional networking?
- Traditional Networking: Each device has its own control plane and makes independent forwarding decisions.
- SDN: The control plane is centralized in an SDN controller, which dictates forwarding decisions for all devices.
How does the SDN controller communicate with devices?
The SDN controller sends control plane functions to each device, allowing centralized network management.
What applications are used to access the management plane of a network device?
- Secure Shell (SSH)
- Trivial File Transfer Protocol (TFTP)
- Secure FTP (SFTP)
- Secure Hypertext Transfer Protocol (HTTPS)
What protocol is commonly used to monitor network devices via the management plane?
Simple Network Management Protocol (SNMP).
How does the SDN controller manage network flows?
1 Each flow traveling through the network must first get permission from the SDN controller.
2 The controller computes a route for the flow and adds an entry in each switch’s flow table.
3 Switches use flow tables to match packets to a flow and specify actions.
What is a flow table in SDN?
A flow table matches incoming packets to a particular flow and specifies the functions to be performed on those packets.
What is a meter table in SDN?
A meter table applies performance-related actions to a flow, including rate-limiting traffic.
How is Cisco ACI different from traditional SDN?
Cisco ACI is a hardware-based SDN solution that integrates cloud computing and data center management.
What are the three core components of Cisco ACI?
- Application Network Profile (ANP)
- Application Policy Infrastructure Controller (APIC)
- Cisco Nexus 9000 Series switches
What is the role of the APIC controller in Cisco ACI?
- The Application Policy Infrastructure Controller (APIC) does not manipulate the data path directly.
- It centralizes policy definition and programs the leaf switches to forward traffic based on policies.
What are the three types of SDN?
- Device-Based SDN – Devices are programmable by applications running on the device itself or on a server in the network.
- Controller-Based SDN – Uses a centralized controller with knowledge of all devices in the network.
- Policy-Based SDN – Similar to controller-based SDN, but includes an additional policy layer that simplifies network-wide policy enforcement.
What is the most robust type of SDN?
Policy-Based SDN, as it provides a simplified mechanism to control and manage policies across the entire network.
What is Cisco APIC-EM?
Cisco Application Policy Infrastructure Controller - Enterprise Module (APIC-EM) is an example of policy-based SDN that provides a single interface for network management.
What are the key functions of Cisco APIC-EM?
-Discovers and accesses device and host inventories
- Views network topology
- Traces paths between endpoints
- Applies and manages policies across the network
What is the function of the APIC-EM Path Trace tool?
- Visualizes traffic flows between two endpoints.
- Detects conflicting, duplicate, or shadowed ACL entries.
- Examines ACLs along the path to identify any security or routing issues.
