Itec 3100 test 1 review

Chapter 1: Introduction

  • Router Simulation Review

    • Reviewing commands covered previously.

    • IP Config Command

      • Displays IP address, subnet mask, and default gateway.

      • Subnet Mask

        • 32 bits long, used to determine the network address from the IP address.

        • Helps sending hosts identify if the packet can be sent directly to a device in the same network or if it needs to go through the default gateway.

        • If in the same network, sent directly; if different, sent to the default gateway.

      • Default Gateway

        • Acts as an access point for devices to send packets outside of their local network.

    • IP Config /all Command

      • Displays all network settings, including the Physical Address (MAC Address)

        • MAC Address

          • Stands for Media Access Control, 48 bits long.

          • Uniquely identifies a device's NIC (Network Interface Card), typically burned into the NIC at manufacture.

    • Number Systems Conversions

      • Binary to Decimal and Decimal to Binary conversions (for IP addresses).

      • Binary to Hexadecimal and vice versa (for MAC addresses).

    • MAC Address Notation

      • Different notations exist depending on the operating system.

      • Examples: Cisco notation, byte-dash notation, and byte-colon notation.

Chapter 2: Same Mac Address

  • MAC Address Representation

    • Different systems (Windows, Mac, Linux) have different formats for representing the same MAC address.

      • Byte-dash representation (e.g., 00-1A-2B-3C-4D-5E).

      • Byte-colon representation (e.g., 00:1A:2B:3C:4D:5E).

  • Ping Command

    • Used to check connectivity between hosts.

    • On Windows: Sends 4 packets by default.

    • On Mac/Linux: Sends packets continuously until interrupted.

    • Provides information on:

      • Active connection status.

      • Network latency (average time for response).

      • TTL (Time to Live)

        • Prevents endless pings from consuming bandwidth.

        • Decrements with each hop and discarded when reaches zero.

Chapter 3: Physical Layer Deals

  • Packet Terminology

    • General term for a packet: PDU (Protocol Data Unit).

    • Ethernet Frame

      • Used at the Data Link Layer (Layer 2).

    • IP Datagram

      • Used at the Network Layer (Layer 3).

  • Packet Structure

    • Composed of header and trailer.

    • Header Contains:

      • Preamble, source and destination MAC addresses (48 bits each), type field (2 bytes).

    • Trailer Contains:

      • FCS (Frame Check Sequence) for error detection (32 bits).

  • Key Protocols

    • IP datagram encapsulates other PDUs (e.g., ICMP).

    • Basic structure of PDUs (TCP, UDP) relevant.

Chapter 4: Know The Layers

  • OSI Model Overview

    • Seven layers of the OSI model:

      1. Physical Layer: Deals with hardware and bit signals.

      2. Data Link Layer: Runs Ethernet protocol, interfaces with hardware.

      3. Network Layer: Handles IP addressing and routing.

      4. Transport Layer: Ensures reliable packet transmission, detects errors.

      5. Session Layer: Maintains context information across sessions (e.g., file downloads).

      6. Presentation Layer: Handles data encryption, compression, and encoding.

      7. Application Layer: Defines network applications and high-level protocols (e.g., HTTP).

    • Reference Model

      • OSI is a framework; TCP/IP model is widely implemented.

  • Switch vs. Router

    • Switch: Layer 2 device; connects devices within a LAN using MAC addresses.

    • Router: Layer 3 device; connects different networks using IP addresses.

  • Communication Types on Switch

    • Simplex (Half Duplex): One-way communication.

    • Duplex: Two-way communication.

Chapter 5: The Mac Address

  • MAC Address Table

    • Switch maps multiple MAC addresses to a single port (Connection to another switch).

    • Switches learn from incoming packets, create or update entries in the MAC address table.

  • Flooding

    • Occurs if a destination MAC address is not found in the table.

    • The frame is sent to all ports, except the one it was received from.

  • Switch Management

    • Configure IP address, subnet mask, and default gateway for remote management.

  • Router Table

    • Built from existing configurations, includes types of routes (static, local, connected).

Chapter 6: Conclusion

  • CLI Navigation

    • User Exec Mode: Password protected, initial access mode.

    • Privileged Exec Mode: More commands available, can view running configuration.

    • Global Configuration Mode: Base mode for configuration.

    • Interface Configuration Mode: Specific to a selected interface.

  • Network Topologies

    • Types:

      • Bus Topology

      • Ring Topology

      • Star Topology

      • Point-to-Point (Mesh) Topology

    • Understand advantages, disadvantages, and best use cases for each topology.