Virtualization and Software Defined Networking

Flashcards reviewing key concepts from lecture notes on virtualization, hypervisors, virtual switches, network virtualization, computer networking planes, software-defined networking (SDN), and software-defined access.

Virtualization

Taking and creating a virtual version of something, such as computers, routers, switches, and storage devices.

Virtual Machine (VM)

Emulation of a physical machine via software.

Desktop Virtualization

VM is created for the purposes of emulating a desktop environment, allowing for multiple VMs with their own OS on a single computer or server.

Server Virtualization

VM is created for the purposes of emulating a server providing a service on a computer network, allowing multiple server VMs on a single server.

Storage Virtualization

Two or more storage drives are logically linked together and presented as a single storage drive.

Application Virtualization

Software application is accessed through a server versus locally on a computer.

Hypervisors

Specialized OSs that are installed directly on physical hardware (bare-metal) and are responsible for creating, managing, and running VMs.

Host Machine

A physical machine with a hypervisor installed running multiple VMs.

Guest Machine

Every VM that has been created and runs on a host machine.

Guest OS

OSs that are installed on the VM and run off the provisioned virtual hardware.

Type-1 Hypervisor (Bare-Metal Hypervisor)

Hypervisor that runs directly off the host machine’s hardware without a native OS being installed beforehand.

Type-2 Hypervisor

Hypervisor that runs off the OS of the host machine, like other software programs.

Host OS

The OS on a host machine.

Virtual Desktop Infrastructure (VDI)

A virtualization setup where the VMs hosted on a dedicated host machine are primarily for desktop usage.

Thin Client

A computer optimized to establish a remote connection to a host machine, running a guest OS hosted on the host machine but requiring a continuous connection.

Thick Client

A computer that does not require continuous connection between itself and a remote server to function.

Virtual Switch

A construct managed internally by the host machine allowing VMs to engage in computer networking. VMs can be assigned to a VLAN and corresponding subnet within it.

Network Virtualization

Host machines create logical switches that are created and shared as if they were a single entity, replacing the concept of a VLAN on the virtual switch to a 1:1 ratio.

Host Protocol for Encapsulation

A host protocol (e.g., VXLAN) used to encapsulate data between VMs on the same logical switch.

Logical Routers

Host machines create these to allow all VMs connected to the logical switches of a host machine to also have virtually connected interfaces for routing services.

Software Defined Networking (SDN)

Technology that provides a method of breaking up traditional planes observed on a piece of network equipment and consolidating them to improve performance in a virtual environment.

Management Plane

The plane on a piece of network equipment responsible for configuration, monitoring, and management services (e.g., Telnet, SSH, SNMP, APIs).

Control Plane

The plane on a piece of network equipment responsible for controlling and providing information to the Data Plane (e.g., routing tables, MAC address tables, topology databases).

Data Plane

The plane on a piece of network equipment responsible for the actual movement of data (Forwarding Plane), including encapsulation and forwarding/discarding PDUs.

Distributed Control Planes

The concept of separate control planes across separate pieces of network equipment.

Controller Based Networking

Removes the traditional distributed control plane architecture and introduces an SDN Controller to manage the control plane for each forwarding device.

Forwarding Device

A piece of network equipment (router or switch) that lacks an independent control plane, as its control plane is managed by the SDN controller.

Centralized Control Plane

Eases network administration and increases network performance by having a single point of control for multiple forwarding devices.

South Bound Interface (SBI)

An interface created between the SDN controller and forwarding device to allow control of it. The control plane of the SDN is then connected logically to the data plane of the forwarding device via this.

OpenFlow

An open-source vendor-neutral protocol providing access to the data plane of a forwarding device for the SDN.

NETCONF

A protocol standardized by the IETF providing access to both the management plane and data plane of a forwarding device for the SDN.

North-Bound Interface (NBI)

An interface created between a network administrator and the SDN controller for configuration purposes, which can be GUI or CLI based.

Routed Port

Physical switchports or router ports that are strictly layer 3, have an IP address assigned to them for facilitating routing, and do not support STP, VLAN memberships, or layer 2 communication.

Spine/Leaf Topology

A network topology which results from merging the access and distribution layers, consisting of leaf switches connecting to endpoint nodes and spine switches representing the core layer.

Leaf Switches

Forwarding devices that endpoint nodes will connect to in a spine/leaf architecture.

Spine Switches

Traditional distribution layer switches that are now representative of the core layer in a spine/leaf topology.

SDN Underlay

The topology that represents the physical forwarding devices which provide connectivity between nodes in SDN.

SDN Overlay

The virtual network created via tunnels by the SDN controller for the forwarding devices on the SDN underlay topology.

Fabric

The presentation of both the underlay and overlay in culmination of each other is.

Fabric Edge Nodes

Another name for Leaf switches in a Fabric.

Fabric Control Node

Another name for SDN control in a Fabric.

Software-Defined Access

The implementation of SDN on a computer network, which revolves around the centralized control plane of the SDN controller.

Location Identity Separation Protocol (LISP)

A protocol running on the centralized control plane of the SDN controller, used to provide host nodes access and connectivity to the SDN computer network.

End-point Identifier (EID)

Identifies and assigns each host node that connects to a fabric edge node (leaf switch).

Routing Locator (RLOC)

The fabric edge node (leaf switch) that the host node is connected to directly.

LISP Table

The database containing the mapping of EIDs to RLOCs, managed on the centralized control plane of an SDN controller.