CCNA 200-301 Official Cert Guide Volume 1 CH1

Chapter 1: Introduction to TCP/IP Networking

1.0 Network Fundamentals

• Introduction to the structure and concepts of networking used in CCNA exam preparation.

• Importance of networking standards and protocols for consistent network functionality.

• Networking models assist in categorizing standards, protocols, and their roles.

1.1 Networking Models

• Networking models act as "blueprints" for building networks, ensuring that different components work together seamlessly.

• TCP/IP is the most prevalent networking model today, supported by nearly all operating systems.

• This chapter focuses on concepts related to the TCP/IP model to help understand CCNA exam topics.

1.2 Comparison of Physical Interfaces and Cabling Types

1.2.1 Cabling Types

• Single-mode fiber, multimode fiber, and copper cabling are essential cabling types in networking.

1.2.2 Connections

• Explains Ethernet shared media vs. point-to-point connections.

• Highlights the differences in performance and application for each cabling type.

1.3 The Evolution of Networking Models

• Overview of the transition from proprietary models to the more universally accepted TCP/IP model.

• Discussion of the International Organization for Standardization (ISO) and its efforts in creating the OSI model.

• Key insights into how TCP/IP emerged as a dominant model by the late 1990s, with various protocols facilitating device communication.

1.4 TCP/IP Networking Model

• TCP/IP comprises several layers, each defining specific functions and protocols for data communication.

• Each layer of TCP/IP has unique responsibilities, from physical transmission to application services.

1.4.1 Layers of the TCP/IP Model

• Application Layer: Provides services to application software; utilizes protocols like HTTP.

• Transport Layer: Responsible for reliable data transfer; main protocols include TCP and UDP.

• Network Layer: Handles addressing and routing data across the network using IP.

• Data Link Layer: Manages device-to-device data transfer over specific media, including Ethernet.

• Physical Layer: Deals with the physical transmission of raw bits over a communication channel.

1.5 Data Encapsulation and Packet Transmission

• Explanation of how data is encapsulated as it moves through the layers of the TCP/IP model.

• Each layer adds its own header (and possibly trailer) to the data being transmitted.

• Terms:

  • Segment: Data unit at the transport layer.

  • Packet: Data unit at the network layer.

  • Frame: Data unit at the data link layer.

1.6 Interaction Between Layers

1.6.1 Same-layer Interaction

• Communication between similar layers on different devices using protocol headers.

1.6.2 Adjacent-layer Interaction

• How one layer on a device requests services from a lower layer (e.g., TCP providing error recovery to HTTP).

1.7 OSI Model Comparison

• The OSI model serves as a historical reference and is critical for understanding terminology in networking, although it is less commonly implemented today.

• Comparison of OSI and TCP/IP layers to highlight similarities and differences.

1.8 Chapter Review

• Encouragement to engage with various review elements to reinforce understanding:

  • Key Topics and their Page Numbers for quick reference:

    • Figure 1-10: Concept of IP routing 29

    • Figure 1-11: Data-link services and IP 30

    • Figure 1-12: Encapsulation steps 32

    • Figure 1-13: Segment, packet, frame definitions 32

    • Figure 1-14: Comparison of OSI and TCP/IP 33

Key Terms to Remember

• Adjacent-layer interaction

• De-encapsulation

• Encapsulation

• Frame

• Networking model

• Packet

• Same-layer interaction

• Segment