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CCNA v3 Semester 1 Module 10 Routing Fundamentals and Subnets

By Tommy Riley,2014-06-17 08:18
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CCNA v3 Semester 1 Module 10 Routing Fundamentals and Subnets ...

CCNA v3 Semester 1 Module 10 Routing Fundamentals and Subnets

    CCNA v3 Semester 1 Module 10 Routing Fundamentals and Subnets ....................... 1 Overview ............................................................................................................... 1 10.1 Routed Protocol ......................................................................................... 2

    10.1.1 Routable and routed protocols ............................................................ 2

    10.1.2 IP as a routed protocol ........................................................................ 3

    10.1.3 Packet propagation and switching within a router ............................... 4

    10.1.4 Connectionless and connection-oriented delivery ............................... 5

    10.1.5 Anatomy of an IP packet .................................................................... 6 10.2 IP Routing Protocols .................................................................................. 8

    10.2.1 Routing overview ............................................................................... 8

    10.2.2 Routing versus switching.................................................................. 10

    10.2.3 Routed versus routing protocols ....................................................... 12

    10.2.4 Path determination ........................................................................... 13

    10.2.5 Routing tables .................................................................................. 15

    10.2.6 Routing algorithms and metrics ........................................................ 16

    10.2.7 IGP and EGP .................................................................................... 17

    10.2.8 Link state and distance vector ........................................................... 18

    10.2.9 Routing protocols ............................................................................. 19 10.3 The Mechanics of Subnetting ................................................................... 20

    10.3.1 Classes of network IP addresses ....................................................... 20

    10.3.2 Introduction to and reason for subnetting .......................................... 20

    10.3.3 Establishing the subnet mask address ............................................... 21

    10.3.4 Applying the subnet mask ................................................................ 23

    10.3.5 Subnetting Class A and B networks .................................................. 24

    10.3.6 Calculating the resident subnetwork through ANDing ...................... 25

    Summary ......................................................................................................... 26

Overview

    Internet Protocol (IP) is the main routed protocol of the Internet. IP addresses are used to route packets from a source to a destination through the best available path. The

    propagation of packets, encapsulation changes, and connection-oriented and

    connectionless protocols are also critical to ensure that data is properly transmitted to its destination. This module will provide an overview for each.

The difference between routing and routed protocols is a common source of confusion.

    The two words sound similar but are quite different. Routers use routing protocols to

    build tables that are used to determine the best path to a host on the Internet.

Not all organizations can fit into the three class system of A, B, and C addresses.

    Flexibility exists within the class system through subnets. Subnets allow network

    administrators to determine the size of the network they will work with. After they

    decide how to segment their networks, they can use subnet masks to determine the

    location of each device on a network.

This module covers some of the objectives for the CCNA 640-801, INTRO 640-821,

    and ICND 640-811 exams.

     - 1 -

    Students who complete this module should be able to perform the following tasks:

; Describe routed protocols

    ; List the steps of data encapsulation in an internetwork as data is routed to Layer

    3 devices

    ; Describe connectionless and connection-oriented delivery

    ; Name the IP packet fields

    ; Describe how data is routed

    ; Compare and contrast different types of routing protocols

    ; List and describe several metrics used by routing protocols

    ; List several uses for subnetting

    ; Determine the subnet mask for a given situation

    ; Use a subnet mask to determine the subnet ID

10.1 Routed Protocol

    10.1.1 Routable and routed protocols

This page will define routed and routable protocols.

    A protocol is a set of rules that determines how computers communicate with each other across networks. Computers exchange data messages to communicate with each other. To accept and act on these messages, computers must have sets of rules that determine how a message is interpreted. Examples include messages used to establish a connection to a remote machine, e-mail messages, and files transferred over a network.

A protocol describes the following:

; The required format of a message

    ; The way that computers must exchange messages for specific activities

    A routed protocol allows the router to forward data between nodes on different networks.

     - 2 -

    A routable protocol must provide the ability to assign a network number and a host number to each device. Some protocols, such as IPX, require only a network number. These protocols use the MAC address of the host for the host number. Other protocols, such as IP, require an address with a network portion and a host portion. These protocols also require a network mask to differentiate the two numbers. The network address is obtained by ANDing the address with the network mask.