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1Networking Devices2Interfaces And Cables3OSI Model and TCP/IP Suite4Intro to the CLI5Ethernet LAN Switching - Part 16Ethernet LAN Switching - Part 27IPv4 Addressing - Part 18IPv4 Addressing - Part 29Switch Interfaces10The IPv4 Header11Routing Fundamentals - Part 111Static Routing - Part 212Life of a Packet13Subnetting - Part 114Subnetting - Part 215Subnetting (VLSM) - Part 316VLANs - Part 117VLANs - Part 218VLANs - Part 319DTP / VTP20Spanning Tree Protocol - Part 121Spanning Tree Protocol - Part 222Rapid Spanning Tree Protocol23Etherchannel24Dynamic Routing25RIP / EIGRP26OSPF - Part 127OSPF - Part 228OSPF - Part 329First Hop Redundancy Protocol30TCP and UDP31IPv6 - Part 132IPv6 - Part 233IPv6 - Part 334Standard Access Control List35Extended Access Control List36CDP and LLDP37NTP - Network Time Protocol38DNS - Domain Name System39DHCP - Dynamic Host Configuration Protocol40SNMP - Simple Network Management Protocol41SYSLOG42SSH - Secure Shell43FTP and TFTP44NAT (Static) - Part 145NAT (Dynamic) - Part 246QoS (Voice VLAN) - Part 147QoS (Quality of Service) - Part 248Security Fundamentals49Port Security50DHCP Snooping51Dynamic ARP Inspection52LAN Architectures53WAN Architectures54Virtualization and Cloud - Part 154Virtualization (Containers) - Part 254Virtualization (VRF) - Part 355Wireless Fundamentals56Wireless Architectures57Wireless Security58Wireless Configuration59Introduction to Network Automation60JSON, XML, and YAML61REST APIs62Software Defined Networking63Ansible, Puppet, and Chef67CCNA Complete Cheatsheet
/Virtualization and Cloud - Part 1
Topic 547 min read

Virtualization and Cloud - Part 1

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54. VIRTUALIZATION AND CLOUD: PART 1

VIRTUAL SERVERS

  • Although Cisco is more known for their networking DEVICES (ROUTERS, SWITCHES, FIREWALLS), they also offer HARDWARE SERVERS such as UCS (Unified Computing System)
  • The largest vendors of HARDWARE SERVERS include Dell, EMC, HPE, and IBM

SERVERS BEFORE VIRTUALIZATION

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  • Before VIRTUALIZATION, there was a one-to-one relationship between a PHYSICAL SERVER and OPERATION SYSTEM
  • In that OPERATING SYSTEM, apps providing SERVICES (such as a WEB SERVER, EMAIL SERVER, etc) would run
  • One PHYSICAL SERVER would be used for the WEB SERVER, one for the EMAIL SERVER, one for the DATABASE SERVER, etc.
  • This is inefficient for multiple reasons:
    • Each PHYSICAL SERVER is expensive and takes up space, power, etc.
    • The RESOURCES on each PHYSICAL SERVER (CPU, RAM, STORAGE, NIC) are typically under-utilized

VIRTUALIZATION (TYPE 1 HYPERVISOR)

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  • VIRTUALIZATION allows us to break the one-to-one relationships of HARDWARE to OS, allowing multiple OS’s to run on a single PHYSICAL SERVER
  • Each INSTANCE is called a VM (Virtual Machine)
  • A HYPERVISOR is used to manage and allocate the HARDWARE RESOURCES (CPU, RAM, etc.) to each VM
  • Another name for a HYPERVISOR is VMM (Virtual Machine Monitor)
  • The type of HYPERVISOR which runs directly on top of hardware is called a TYPE 1 HYPERVISOR
    • Examples include : VMware ESXi, Microsoft Hyper-V, etc.
  • TYPE 1 HYPERVISORS are also called bare-metal hypervisors because they run directly on the hardware (metal).
    • Another term is native hypervisor
  • This is the type of HYPERVISOR used in data center environments

VIRTUALIZATION (TYPE 2 HYPERVISOR)

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  • TYPE 2 HYPERVISORS run as a program on an OS like a regular computer program
    • Examples: VMware Workstation, Oracle Virtualbox, etc
  • The OS running directly on the hardware is called the HOST OS
  • The OS running in a VM is called a GUEST OS
  • Another name for a TYPE 2 HYPERVISOR is hosted hypervisor
  • Although TYPE 2 HYPERVISORS are rarely used in data center environments, they are common on personal-use devices (for example, if a MAC/Linux user needs to run an app that is only supported on Windows, or vice-versa)

WHY VIRTUALIZATION?

  • PARTITIONING :

    • Run multiple OS’s on ONE PHYSICAL MACHINE
    • Divide system resources between VIRTUAL MACHINES

  • ISOLATION :

    • Provide FAULT and SECURITY ISOLATION at the hardware level
    • Preserve performance with advanced resource controls

  • ENCAPSULATION :

    • Save the entire state of a virtual machine to files
    • Move and copy virtual machines as easily as moving and copying files

  • HARDWARE INDEPENDENCE :

    • Provision or migrate any virtual machine to any physical server

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VIRTUAL NETWORKS

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  • VMs are connected to each other and the EXTERNAL NETWORK via a VIRTUAL SWITCH running on the HYPERVISOR
  • Just like a regular PHYSICAL SWITCH, the vSWITCH’s INTERFACES can operate as ACCESS PORTS or TRUNK PORTS and use VLANs to separate the VMs at LAYER 2
  • INTERFACES on the vSWITCH connect to the PHYSICAL NIC (or NICs) of the SERVER to communicate with the EXTERNAL NETWORK

INTRO TO CLOUD COMPUTING

  • Traditional IT infrastructure deployments were some combination of the following:

    • ON-PREMISES

      • All SERVERS, NETWORK DEVICES, and other infrastructure are located on company property
      • All equipment is purchased and owned by the company using it
      • The company is responsible for the necessary space, power, and cooling

    • CO-LOCATION

      • Data centers that rent out space for customers to put their infrastructure (SERVERS, NETWORK DEVICES)
      • The data center provides the space, electricity, and cooling
      • The SERVERS, NETWORK DEVICES, etc are still the responsibility of the end customer, although they are not located on the customer’s premises
  • CLOUD SERVICE provide an alternative that is hugely popular and is continuing to grow
    • Most people associate “CLOUD” with PUBLIC CLOUD PROVIDERS such as AWS
      • Although this is the most common USE of CLOUD SERVICES, it’s not the only one

CLOUD SERVICES

  • The American NIST (National Institute of Standards and Technology) defined cloud computing in SP (Special Publication) 800-145

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  • To understand what the CLOUD is, let’s look at the following outlined in SP 800-145:
    • FIVE ESSENTIAL CHARACTERISTICS
    • THREE SERVICE MODELS
    • FOUR DEPLOYMENT MODELS

THE FIVE ESSENTIAL CHARACTERISTICS OF CLOUD

  • ON-DEMAND SELF-SERVICE

    • The CUSTOMER is able to use the SERVICE (or stop the SERVICE) freely (via a web portal) without direct communication to the SERVICE PROVIDER

  • BROAD NETWORK ACCESS

    • The SERVICE is available through standard NETWORK connections (ie: the Internet or PRIVATE WAN) and can be access through many kinds of DEVICES

  • RESOURCE POOLING

    • A POOL of RESOURCES is provided by the SERVICE PROVIDER and when a CUSTOMER requests a SERVICE (for example creates a new VM), the RESOURCES to fulfill that request are allocated from the shared POOL

  • RAPID ELASTICITY

    • CUSTOMERS can quickly expand the SERVICE they use in the CLOUD (for example: add new VMs, expand STORAGE, etc) from a POOL of RESOURCES that appear to be infinite. Likewise, they can quickly reduce their SERVICES when not needed

  • MEASURED SERVICE

    • The CLOUD SERVICE PROVIDER measures the CUSTOMER’s usage of CLOUD RESOURCES and the CUSTOMER can measure their own use as well. CUSTOMERS are charged based on usage (for example: X Dollars per Gigabyte of STORAGE per day)

THE THREE SERVICE MODELS OF THE CLOUD

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  • In CLOUD COMPUTING, everything is provided on a “SERVICE” model

  • For example: rather than the END USER buying a PHYSICAL SERVER, mounting it on a rack, installing the hypervisor, creating the VM, etc. the SERVICE PROVIDER offers all of this as a SERVICE

  • There are a variety of SERVICES referred to as “___________ as a SERVICE” or “__aaS”

  • The THREE SERVICE MODELS of CLOUD COMPUTING are:

    SOFTWARE as a SERVICE (SaaS) - Example : MS Office 365

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Code
PLATFORM as a SERVICE (PaaS) - Examples : AWS Lambda and Google App Engine

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Code
INFRASTRUCTURE as a SERVICE (Iaas) - Examples: Amazon EC2 and Google Compute Engine

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DEPLOYMENT MODELS

  • Most people assume that “CLOUD” means PUBLIC CLOUD PROVIDERS like AWS, AZURE, and GCP

  • Although “PUBLIC CLOUD” is the most common deployment model, it’s not the ONLY one

  • The FOUR DEPLOYMENT MODELS of CLOUD COMPUTING are:

  • PRIVATE CLOUD

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  • PRIVATE CLOUDS are generally only used by large enterprises

  • Although the CLOUD is PRIVATE, it may be owned by a THIRD PARTY

    • For example: AWS provides PRIVATE CLOUD SERVICES for the American DoD

  • PRIVATE CLOUDS may be ON or OFF PREMISES

    • Many people assume “CLOUD” and “ON-PREM” are two different things but that is not always the case

  • The same kind of SERVICES offered are the same as in PUBLIC CLOUDS (SaaS, PaaS, IaaS) but the infrastructure is reserved for a SINGLE ORGANIZATION

  • COMMUNITY CLOUD

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  • Least common CLOUD deployment

  • Similar to PRIVATE CLOUD, but the INFRASTRUCTURE is reserved for use by a SPECIFIC GROUP or ORGANIZATION

  • PUBLIC CLOUD

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  • The most common CLOUD deployment

  • Popular PUBLIC CLOUD service providers include:

    • AWS
    • MS AZURE
    • GCP (Google Cloud Platform)
    • OCI (Oracle Cloud Infrastructure)
    • IBM Cloud
    • Alibaba Cloud

  • HYBRID CLOUD

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Code
- Basically ANY combination of the preview THREE DEPLOYMENT TYPES
- Example: A PRIVATE CLOUD which can offload to a PUBLIC CLOUD when necessary

BENEFITS OF CLOUD COMPUTING

  • COST

    • CapEx (Capital Expense) of buying HARDWARE and SOFTWARE, setting up DATA CENTERS, etc. are reduced or eliminated

  • GLOBAL SCALE

    • CLOUD SERVICES can scale GLOBALLY at a rapid pace. SERVICES can be set up and offered to CUSTOMERS from a geographic location close to them

  • SPEED / AGILITY

    • SERVICES are provide ON DEMAND and vast amounts of RESOURCES can be provisioned within minutes

  • PRODUCTIVITY

    • CLOUD SERVICES remove the need for many time-consuming tasks such as procuring physical servers, racking them, cabling, installing and updating equipment, etc.

  • RELIABILITY

    • Backups in the CLOUD are very easy to perform. Data can be mirrored at multiple sites in different geographic locations to support disaster recovery

CONNECTION TO PUBLIC CLOUDS

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