CCNA 200-301: Routing and Network Fundamentals

Jul 3, 2024

CCNA 200-301: Routing and Network Fundamentals 📡

Introduction

  • Lecturer's Background: Bachelor's in Computer Information Systems; pursued Master's in Network Security; switched focus to certifications.
  • Key Certifications: A+, Security+, various Cisco and Microsoft certifications.
  • Experienced in working for Fortune 500 companies and teaching CCNA/CCNP for over 12 years.
  • Goal: Help students succeed by focusing on certifications.

Course Structure

Sections Overview

  1. Network Fundamentals
  2. LAN (Wired/Wireless)
  3. WAN (Routing)
  4. IP Services
  5. Security Fundamentals
  6. Network Automation

Section 1: Network Fundamentals

OSI Model Deep Dive

  • OSI Model Layers: Application, Presentation, Session, Transport, Network, Data Link, Physical.
  • Network Elements: Rules, Medium, Messages, Devices.
  • Communication Breakdown: Bob and Alice scenario explaining message transfer.
  • Model Explanation: Switch creates LAN; Router creates WAN (Connecting LANs).
  • TCP/IP Model: Comparison with OSI; five-layer TCP/IP model used today.
  • Encapsulation Process: Data encapsulation with headers at different layers.
  • Purpose of OSI Model: Interoperability, Common Language, Troubleshooting.

Layer Details

Application Layer (Layer 7)

  • DNS: Transforms domain names into IP addresses.
  • DHCP: Dynamically assigns IP addresses to clients (DORA process).

Transport Layer (Layer 4)

  • Port Numbers: Unique identifiers for application sessions.
  • Common Protocols: TCP (reliable, connection-oriented), UDP (unreliable, connectionless).
  • TCP Details:
    • Sequencing, acknowledgments, and windowing.
    • Three-way handshake (SYN, SYN-ACK, ACK).
    • Connections and Port Numbers.

Network Layer (Layer 3)

  • IP Addressing and Path Determination.
  • Packet forwarding and routing.
  • Connection-less, best-effort delivery; media independent.
  • IP Header: Source/Destination addresses; TTL; Protocol.
  • Routing Process: Determines optimal paths and forwards frames.
  • Routing Protocols:
    • RIP, EIGRP, OSPF, ISIS, BGP.

Data Link Layer (Layer 2)

  • Divided into: LLC (talks to Layer 3), MAC (media access control, hardware address, Ethernet).
  • Ethernet Standards: Various IEEE 802.3 standards.
  • LAN Technologies: Ethernet, Token Ring (obsolete), FDDI (obsolete).

Physical Layer (Layer 1)

  • Encoding and Signaling on physical media.
  • Types of Signals: Electrical, Light Pulses (fiber), Radio Waves (Wireless).
  • Physical Media: UTP (most common), Coaxial, Fiber Optic (single/multi-mode).
  • Ethernet Standards: 10BASE-T (Ethernet), 100BASE-TX (Fast Ethernet), 1000BASE-T (Gigabit Ethernet).
  • Extended Network Design:
    • Modular Campus Design: Access, Distribution, Core layers for scalability.
    • Two-Tier vs Three-Tier Network Designs.

WAN Overview

  • WAN Technologies:
    • Dedicated & Switched (Circuit & Packet switched).
    • Broadband Technologies: DSL, Cable, Wireless (3G/LTE/5G).
    • Metro Ethernet: E-Line (Point-to-Point) vs E-LAN (Point-to-Multipoint), E-Tree.
  • MPLS: Transport independent, end-to-end QoS, network topology control.
  • SoHo Architecture: DSL, Cable, Wireless WAN connections.

Section 2: LAN (Wired/Wireless)

Switching Fundamentals

  • Switching Basics: Forwarding frames via MAC address tables.
  • Link Aggregation: EtherChannel, Pack-P (Cisco proprietary), LACP (industry standard).

VLANs

  • Logical segmentation within a LAN.
  • VLAN Types: Data, Voice, Native.
  • Trunking: 802.1Q encapsulation, Native VLAN.
  • VTP: Propagates VLANs across switches, prone to misconfiguration.
  • STP/RSTP: Prevents loops, ensures a loop-free topology.

Wireless Technology

  • Wireless LAN Basics: Half-duplex communication, CSMA/CA.
  • Wireless Standards: 802.11x, range, and throughput considerations.
  • Deployment Models:
    • Autonomous APs vs Lightweight APs.
    • Controllers: Centralized management within networks.
  • Security: WPA2, WPA3 standards.

Section 3: WAN (Routing)

IP Addressing & Subnetting

  • Structured IP Addressing: Classes A, B, C, D, E.
  • Subnet Masks: Subnet vs whole network.
  • Binary Math: Critical skill for subnetting.
  • Private vs Public IPs: RFC 1918 definitions for private addresses.
  • NAT: Translates private addresses to public.
  • Subnetting practice examples: Multiple exercises converting binary, defining ranges.

Dynamic Routing (OSPF)

  • Routing Basics: Static vs dynamic, administrative distance, metrics.
  • OSPF Fundamentals: Link-state protocol, utilizes SPF algorithm, multicasting for efficiency.
  • OSPF Structures: Areas, LSA types, Router IDs.
  • OSPF Configuration: Network commands, reference bandwidth, route summarization.
  • Neighbor Adjacency: Hello packets, neighbor tables, exchange states.
  • Show commands: Verify OSPF setup, routing table overview.