Network Fundamentals – Chapter 2

© 2006 Cisco Systems, Inc. All rights reserved. Cisco PublicITE I Chapter 6 1

Communicating over the Network

Network Fundamentals – Chapter 2

© 2006 Cisco Systems, Inc. All rights reserved. Cisco PublicITE 1 Chapter 6 2

Objectives Identify the structure of a network, including the

devices and media that are necessary for successful communications.

Identify the function of protocols in network communications.

Identify the advantages of using a layered model to describe network functionality.

Identify the role of each layer in two recognized network models: The TCP/IP model and the OSI model.

Identify the importance of addressing and naming schemes in network communications.


Network Structure Elements of communication


Network Structure How messages are communicated


Network Structure Components of a network

Software: Network applications i.e. Web Server(http), File Transfer (FTP), Internet

Relay chat (IRC), Domain Name Translation (DNS), Email (SMTP)

Hardware: Laptop, PC , NIC, Repeater, Hub switch, modem, Wireless routers

Communications servers, Routers, cables, Free space


Network Structure End Devices and their Role in the Network


Network StructureIntermediary devices connect the individual hosts to the network and can

connect multiple individual networks to form an internetwork.

Examples: Network Access Devices (Hubs, switches, and wireless access points)

Internetworking Devices (routers)

Communication Servers and Modems

Security Devices (firewalls)


Network Types Local Area Networks (LANs) Topologies include:

•Star

•Mesh

•Ring


Network Types Wide Area Networks (WANs)


Network Types Internet


Network Types Network Icons


Function of Protocol in Network Communication Protocols and layered models facilitate communication

over data networks


Function of Protocol in Network Communication Network protocols


Function of Protocol in Network Communication Different protocols interact between layers


Function of Protocol in Network Communication Protocols allow Technology independence


Layers with TCP/IP and OSI Model Layered models facilitate complex design from multiple

vendors


Layers with TCP/IP and OSI Model TCP/IP Model (Working model of the Internet)


Layers with TCP/IP and OSI Model Communication Process is through each layer


Layers with TCP/IP and OSI Model Protocol data units (PDU) and encapsulation


Layers with TCP/IP and OSI Model Process of sending and receiving messages


Layers with TCP/IP and OSI Model Protocol and reference models


Layers with TCP/IP and OSI Model OSI Model Layers


Layers with TCP/IP and OSI Model Comparison of OSI and TCP/IP model


Addressing and Naming Schemes Encapsulation headers are used to manage

communication in data networks

•Allows data to move between end devices using MAC addressing and IP addressing


Addressing and Naming Schemes Getting the Data to the end Device on Data-Link Layer


Addressing and Naming Schemes Getting the Data through the Internetwork


Addressing and Naming Schemes Port numbers are used to identify the destination

application

FTP (21),SSH(22),Telnet(23), Email(25), http(80) www(8080) IRC(6667)


IP addressing Basics








Example

Example: For the address 192.168.1.3

Determine:

The length of the subnet mask in bits.

The Subnet mask format in dotted decimal format

The class of the address

The number of bits in the host portion

The network address


Solution


Solutions

The length of the subnet mask in bits. (24)

The Subnet mask format in dotted decimal format (255.255.255.0)

The class of the address (C)

The number of bits in the host portion (8 bits)

The network address (192.168.1.0 i.e. when all the host bits are 0)


Network Models and Protocols

2.6.2 Using Wireshark to vew PDUs

3.4.2 Managing a small web server

(Applications, Addressing, Protocols, connectivity)

Education

Network Fundamentals – Chapter 2