Chapter 1 of 5 · CompTIA Network+ N10-009

Networking Concepts

OSI, devices, cloud, ports, media, topologies, IP addressing and modern designs.

  • 11topics
  • 53 minfast track
  • 4diagrams and exhibits
  • 23%of the exam
Start with The OSI Reference Model

Topics in this chapter

Take them in order, or jump to the one you need.

  1. 1The OSI Reference ModelLearn the seven OSI layers, the data unit and typical devices at each layer, and how encapsulation and decapsulation carry data…Diagram5 min
  2. 2Networking Appliances and FunctionsCompare routers, switches, firewalls, IDS and IPS, load balancers, proxies, access points, NAS and SAN, plus CDN, VPN, QoS and…5 min
  3. 3Cloud Concepts and ConnectivityKnow cloud deployment and service models, scalability, elasticity, multitenancy, infrastructure as code and the VPN or private…Diagram5 min
  4. 4Common Ports and ProtocolsMemorize the well known ports for FTP, SSH, Telnet, SMTP, DNS, DHCP, HTTP, HTTPS, NTP, SNMP, LDAP and RDP, and learn the secure…4 min
  5. 5IP Protocol Types and Traffic TypesCompare TCP, UDP, ICMP, GRE and IPsec protocol types and the unicast, multicast, anycast and broadcast traffic types used on IP…4 min
  6. 6Transmission Media and TransceiversCompare copper categories, fiber types, coax, connectors, SFP transceivers, termination standards, wireless and satellite media…5 min
  7. 7Topologies and Network ArchitecturesCompare star, mesh, bus, ring and hub and spoke topologies with three tier, collapsed core and spine and leaf designs, and north…Diagram5 min
  8. 8Network Types and WAN LinksCompare LAN, WAN, MAN, WLAN, PAN, CAN and SAN types, client server and peer to peer models, WAN technologies, provider links and…5 min
  9. 9IPv4 Addressing and SubnettingLearn IPv4 address classes, private and special ranges, subnet masks, CIDR notation, VLSM and how to work out hosts, networks and…5 min
  10. 10IPv6 Addressing and TransitionLearn IPv6 address format and shortening rules, address types, neighbor discovery, and the dual stack, tunneling and NAT64…5 min
  11. 11Modern Network Use CasesSummarize SDN, SD-WAN, VXLAN, zero trust architecture, SASE and SSE, and infrastructure as code with automation and orchestration…5 min

About this chapter

What this chapter covers

Networking Concepts is the foundation of the Network+ N10-009 exam. It explains the vocabulary and building blocks that every later chapter uses.

The chapter follows the first exam domain. It covers the Open Systems Interconnection (OSI) model, networking devices, cloud models, ports and protocols, cabling and transceivers, network layouts, IPv4 and IPv6 addressing, and modern technologies such as software defined networking.

How the topics fit together

The pages start with the model that describes how data moves, then look at the devices, services and media that carry it, and end with addressing and newer designs.

OSI modellayers and unitsdescribesDevices and cloudappliances and servicesusePorts and mediaprotocols and cablesorganized asTopologieslayouts and WANaddressed byIP addressingIPv4 and IPv6
  • The OSI model gives you a layer number for every device, protocol and fault.
  • Appliances and cloud show which device or service does which job.
  • Ports, protocols and traffic types tell you how applications are identified and delivered.
  • Media and transceivers cover the physical layer, from copper categories to fiber modules.
  • Topologies and WAN links cover how sites and devices are laid out and connected.
  • IPv4, IPv6 and modern use cases finish with addressing and the newer designs.
Exam tip

Memorize the port table and the private IPv4 ranges early. They come up in many questions across all five chapters.

How to use these pages

Each topic page has the same shape, so you can skim for what you need.

  • What it is: the idea in plain words.
  • How it works: the mechanism, with diagrams, tables and example commands.
  • What to remember for the exam: the facts to memorize.
  • Common mistakes: the classic traps.
  • Check yourself: three questions to test your understanding.

Read the pages in order the first time. Then use the exam facts and the questions for revision.

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