CCNA Notes

200-301 Exam Prep

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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 (Containers) - Part 2
Topic 543 min read

Virtualization (Containers) - Part 2

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54. VIRTUALIZATION (CONTAINERS): PART 2

REVIEW OF VIRTUAL MACHINES (TYPE 1 and TYPE2 HYPERVISORS)

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  • VIRTUAL MACHINES (VMs) allow multiple OS’s to run on a single PHYISCAL SERVER

  • A HYPERVISOR is used to manage and allocate HARDWARE RESOURCES to each VM

    • TYPE 1 HYPERVISORS (aka NATIVE or BARE-METAL) run directly on top of HARDWARE
    • TYPE 2 HYPERVISORS (aka HOSTED) run on top of a HOST OS (ie: WINDOWS)

  • TYPE 1 HYPERVISORS are widely used in DATA CENTER ENVIRONMENTS

  • TYPE 2 HYPERVISORS are commonly used on personal DEVICES

    • Running a virtual network lab on your PC using Cisco Modeling Labs (CML)

  • The OS in each VM can be the same or different (Windows, Linux, MacOS, etc)

  • Bins / Libs are the SOFTWARE libraries / services needed by the Apps running in each VM

  • A VM allows it’s app / apps to run in an ISOLATED environment, separate from the apps in other VMs.

  • VMs are easy to create, delete, move, etc.

    • A VM can be easily saved and moved between different physical SERVERS.

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CONTAINERS

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  • CONTAINERS are software packages that contain an APP and all dependencies (Bins/Libs in the diagram) for the contained APP to run.
    • Multiple APPS can be run in a single CONTAINER, but this is not how CONTAINERS are usually used
  • CONTAINERS run on a CONTAINER ENGINE (ie: DOCKER ENGINE)
    • The CONTAINER ENGINE is run on a HOST OS (usually LINUX)
  • CONTAINERS are lightweight (small in size) and include only the dependencies required to run the specific APP
  • A CONTAINER ORCHESTRATOR is a software platform for automating the DEPLOYMENT, MANAGEMENT, SCALING, etc of CONTAINERS
    • KUBERNETES (originally design by Google) is the most popular CONTAINER ORCHESTRATOR
    • DOCKER SWARM is DOCKER’S CONTAINER ORCHESTRATION tool
  • In small numbers, MANUAL operation is possible, but large-scale systems (ie: with Microservices) can require THOUSANDS of CONTAINERS

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VIRTUAL MACHINES vs. CONTAINERS

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  • VMs can TAKE MINUTES to boot up as each VM runs it’s own OS

  • CONTAINERS can boot up in milliseconds

  • VMs take MORE disk space (Gigabytes)

  • CONTAINERS take up VERY LITTLE disk space (Megabytes)

  • VMs use MORE CPU/RAM resources (each VM must run its own OS)

  • CONTAINERS use FEWER CPU/RAM resources (shared OS)

  • VMs are PORTABLE and can MOVE between physical systems running the same HYPERVISOR

  • CONTAINERS are MORE portable; they are SMALLER, FASTER to boot up, and DOCKER CONTAINERS can be run on nearly ANY CONTAINER SERVICE

  • VMs are more isolated because each VM runs it’s own OS

  • CONTAINERS are less isolated because they all run on the same OS; if the OS crashes, all CONTAINERS running on it are effected

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