Cisco Certified Network Associate (CCNA) Network Fundamentals Syllabus

Network Fundamentals syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Network Fundamentals in Cisco Certified Network Associate (CCNA), not a summary of it.

1. 1

   Networking Concepts and Models

   4 topics

   • Role and function of network components
     • Routers
     • Layer 2 and Layer 3 switches
     • Next-generation firewalls and IPS
     • Access points, WLCs, and endpoints
     • Servers, PoE, and power over Ethernet basics
   • OSI and TCP/IP reference models
     • Seven OSI layers and their functions
     • TCP/IP layer mapping
     • Encapsulation and de-encapsulation (PDUs)
   • Network topology architectures
     • Two-tier and three-tier hierarchical design
     • Spine-leaf data center fabric
     • WAN, SOHO, and small office designs
     • On-premises vs cloud architectures
   • Characterizing network types and traffic
2. 2

   Physical Interfaces and Cabling

   3 topics

   • Copper and fiber media selection
     • Single-mode vs multimode fiber
     • Copper categories and distance limits
     • Choosing media for a given scenario
   • Connection types and transceivers
     • Ethernet shared media vs point-to-point
     • Straight-through vs crossover cabling
   • Interface and cable troubleshooting
     • Collisions and late collisions
     • Duplex and speed mismatches
     • Errors, runts, giants, and CRC
3. 3

   IPv4 Addressing and Subnetting

   4 topics

   • IPv4 address structure and classes
     • Network, host, and broadcast portions
     • Private vs public address ranges
   • Subnetting and VLSM
     • Subnet masks and prefix notation
     • Calculating subnets and host counts
     • Variable-length subnet masking
   • Address conservation techniques
     • Need for private addressing and NAT
   • Verifying IPv4 connectivity and configuration
4. 4

   IPv6 Addressing

   4 topics

   • IPv6 address format and compression
     • Hextet notation and zero compression rules
     • Prefix and interface ID structure
   • IPv6 address types
     • Global unicast and unique local
     • Link-local addresses
     • Multicast and anycast
   • IPv6 address assignment
     • SLAAC and EUI-64
     • Stateful and stateless DHCPv6
     • Static configuration
   • Verifying IPv6 addressing and neighbors
5. 5

   Wireless Fundamentals and Virtualization

   3 topics

   • Wireless principles
     • Nonoverlapping 2.4 GHz channels (1, 6, 11)
     • 5 GHz channels and channel width
     • SSID, RF, and encryption basics
   • Virtualization fundamentals
     • Server virtualization and hypervisors
     • Containers
     • Virtual networks (VRFs concept)
   • Switching concepts
     • MAC address learning and aging
     • Frame switching and flooding
     • Frame forwarding and the MAC table

Network Fundamentals flashcards for Cisco Certified Network Associate (CCNA)

22 of 52 cards from the Network Fundamentals deck — real questions with worked answers.

1. What is the primary function of a router in a network?

   A router operates at Layer 3 (Network) to forward packets between different IP networks/subnets, determining the best path using a routing table and providing connectivity between LANs and WANs.

2. What is the primary function of a Layer 2 switch?

   A switch forwards frames within a LAN based on destination MAC addresses, building a MAC address table, segmenting collision domains (one per port), and forwarding within a single broadcast domain.

3. What is the function of a firewall in a network?

   A firewall controls and filters traffic between network segments based on a security policy (rules on addresses, ports, protocols, and state), enforcing a boundary between trusted and untrusted networks.

4. What does a Wireless LAN Controller (WLC) do?

   A WLC centrally manages multiple lightweight access points (LWAPs), handling configuration, RF management, client authentication, roaming, and policy enforcement, typically using the CAPWAP protocol.

5. What is the function of an access point (AP)?

   An AP connects wireless clients to a wired network, acting as a bridge between the 802.11 wireless medium and the wired LAN at Layer 2.

6. List the 7 layers of the OSI model from Layer 7 to Layer 1.

   Application, Presentation, Session, Transport, Network, Data Link, Physical (mnemonic: All People Seem To Need Data Processing).

7. What are the Protocol Data Units (PDUs) at the Transport, Network, and Data Link layers?

   Transport = Segment (TCP) / Datagram (UDP); Network = Packet; Data Link = Frame; Physical = Bits.

8. What are the 4 layers of the TCP/IP model and how do they map to OSI?

   Application (OSI 5-7), Transport (OSI 4), Internet (OSI 3), Network Access/Link (OSI 1-2).

9. Compare TCP and UDP.

   TCP is connection-oriented, reliable, uses sequencing, acknowledgments, and flow control (3-way handshake); UDP is connectionless, unreliable, low-overhead, and fast with no guaranteed delivery.

10. What is encapsulation in the OSI model?

    The process of adding protocol header (and trailer) information at each layer as data moves down the stack from application to physical; de-encapsulation reverses it on the receiving side.

11. Describe a star (hub-and-spoke) topology.

    All devices connect to a central node (switch/hub). It is easy to manage and a single link failure isolates only one device, but failure of the central node takes down the whole network.

12. What characterizes a full-mesh topology and how many links does it need?

    Every device connects directly to every other device, providing maximum redundancy. Number of links = n(n-1)/2 for n devices.

13. What is a three-tier (core, distribution, access) hierarchical network design?

    Access layer connects end devices; Distribution layer aggregates access switches and applies policy/routing; Core layer provides high-speed backbone switching between distribution blocks.

14. What is a collapsed core (two-tier) design?

    A design that combines the core and distribution layers into a single layer, used in smaller networks to reduce cost and complexity while keeping a separate access layer.

15. What is a spine-leaf topology and where is it used?

    A two-tier data center fabric where every leaf switch connects to every spine switch (but leaves/spines don't interconnect among themselves), giving predictable low latency and consistent hop count for east-west traffic.

16. Define LAN, WAN, and MAN.

    LAN: high-speed network over a small area (building/campus); WAN: connects networks over large geographic distances, often via service providers; MAN: spans a city/metropolitan area.

17. What is north-south vs east-west traffic?

    North-south traffic flows between clients and servers across the network edge (in/out of the data center); east-west traffic flows server-to-server within the data center.

18. Compare copper UTP and fiber-optic cabling.

    Copper UTP is cheaper, easy to terminate, but limited to ~100m and susceptible to EMI; fiber supports much longer distances and higher bandwidth, immune to EMI, but costs more and is harder to splice.

19. What is the maximum cable length for Ethernet over copper UTP (e.g., Cat5e/Cat6)?

    100 meters (with up to 90m of solid horizontal cabling plus 10m of patch cords).

20. Compare single-mode fiber (SMF) and multimode fiber (MMF).

    SMF has a small ~9µm core, uses a laser, and supports very long distances (km to tens of km); MMF has a larger ~50/62.5µm core, uses LED/VCSEL, costs less, but is limited to shorter distances (hundreds of meters).

21. What is the difference between a straight-through and a crossover Ethernet cable?

    Straight-through connects unlike devices (PC-to-switch, switch-to-router); crossover connects like devices (switch-to-switch, PC-to-PC). Modern devices with Auto-MDIX negotiate this automatically.

22. What does an SFP transceiver do and what is its benefit?

    A Small Form-factor Pluggable is a hot-swappable module inserted into a switch/router port that converts electrical signals to optical (or copper), allowing flexible media/distance choices on the same port.

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