Transcript Year 1 - Module 1 Introduction to Networking

CCNA 1 Chapter 1
Introduction to Networking
By
Your Name
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Objectives
• The connection to the Internet
• Networking math
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Requirements for
Internet Connection
• Connection to the Internet can be broken down
into the following:
– Physical connection
• Used to transfer signals between PCs within the local
network and to remote devices on the Internet
– Logical connection
• Uses standards called protocols. A protocol is a formal
description of a set of rules and conventions that govern how
devices on a network communicate.
– The application
• Interprets the data and displays the information in an
understandable form
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PC Basics
• Electronic components
– Connector, IC, LED, resistor, transistor
• Personal computer subsystems
– Bus, CD-ROM drive, CPU, disk drives,
microprocessor, motherboard, RAM, ROM
• Backplane components
– Mouse port, network card, parallel port
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All Computers Have a CPU, Memory,
Storage, and Interfaces
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Network Interface Cards
• When you select a
network card,
consider the following
three factors:
– Type of network
– Type of media
– Type of system bus
• Installing a NIC in a
PC
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NIC and Modem Installation
• Connectivity to the
Internet requires an
adapter card, which may
be a modem or NIC.
• Notebook computers may
have a built-in interface or
use a PCMCIA card.
Desktop systems may
use an internal or
external NIC.
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High-Speed and Dialup
Connectivity
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TCP/IP Description and Configuration
• Transmission Control Protocol/Internet Protocol
(TCP/IP) is a set of protocols or rules developed
to allow cooperating computers to share
resources across a network.
• To enable TCP/IP on the workstation, it must be
configured using the operating system tools.
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Testing Connectivity with Ping
• Ping is a program that is
useful for verifying a
successful TCP/IP
installation.
• It works by sending
multiple IP packets to a
specified destination.
• Each packet sent is a
request for a reply. Each
reply contains the
success ratio and roundtrip time to the
destination.
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Web Browser and Plug-Ins
• Web browsers
– A web browser acts on
behalf of a user by
•
•
•
•
Contacting a web server
Requesting information
Receiving information
Displaying the results on a
screen
• Plug-ins
– Flash/Shockwave,
QuickTime, Real Audio
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Number Systems
• Knowing what base someone refers to
– Decimal uses 10 digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.
– Binary uses 2 digits: 0 and 1.
• Base conventions
– 101 in base 2 is spoken as one zero one.
• Working with exponents
– 103 = 10 X 10 X 10 = 1000
– 24 = 2 x 2 x 2 x 2 = 16
• Binary numbers
– Use principle of place value just as decimal numbers do
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Binary Number System
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Bits and Bytes
• Bits are binary digits. They are either 0s or 1s. In
a computer, they are represented by On/Off
switches or the presence or absence of electrical
charges, light pulses, or radio waves.
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Base 10 Numbers
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Base 10 Calculations
•
•
The upper table shows the
actual math.
The lower table is a
simplified version that
requires the following:
– Start the value row and
position row with 1 in the
rightmost box.
– Each subsequent value is
current value times the
base (10 in this case).
– Value to be calculated is
entered in the digit row.
– Multiply digit amount times
value entry above.
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Base 2 Table
27
128
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26
64
25
32
24
16
23
8
22
4
21
2
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20
1
Base 2 (Binary) Numbers
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Base 2 Calculations
8-Bit Values
Binary Value: 10101010
Start the value row and
position row with 1 in the
rightmost box.
Each subsequent value is
the current value times the
base (2 in this case).
Binary Value: 11101001
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Converting Decimal to Binary
Example: 35 = 32 + 2 + 1 = 00100011
27
128
26
64
25
32
24
16
23
8
22
4
21
2
20
1
0
0
1
0
0
0
1
1
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Converting Decimal to Binary
Start by dividing the decimal by the largest number in
the Value row that will go.
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Looking At the Table
Relationships
The table will work with larger numbers, such as
this 12-bit example.
For any number in the value row,
the sum of all numbers to the
right is the current value minus 1
(64 - 1 = 63).
Sometimes its easier to subtract the 0 values
from 255 (largest 8-bit value).
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Powers of 2
Powers of 2 are used extensively in networking.
One solution:
1. Start with 2 (which is 21).
2. Double the number to get the next value.
3. If you need 26, continue until you have 6 values.
Look over the example to the right. The second
column is included only for reference.
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Converting 8-Bit Binary to Decimal
• Binary numbers are converted to decimal
numbers by multiplying the binary digits by the
base number of the system, which is base 2,
and raised to the exponent of its position.
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Four-Octet Dotted-decimal
Representation of 32-Bit Binary
Numbers
• Split the binary number into four groups of eight
binary digits. Then convert each group of eight
bits, also known as an octet into its decimal
equivalent.
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Hexadecimal
• The base 16, or
hexadecimal (hex),
number system is
used frequently when
working with
computers, because it
can be used to
represent binary
numbers in a more
readable form.
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Boolean or Binary Logic
• Boolean logic is based on
digital circuitry that
accepts one or two
incoming voltages.
• Boolean logic is a binary
logic that allows two
numbers to be compared
and generate a choice
based on the two
numbers.
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IP Addresses and Network Masks
• When IP addresses are
assigned to computers, use
a portion of the bits on the
left side of the 32-bit IP
number to represent a
network.
• The bits left over in the 32bit IP address identify a
particular computer on the
network.
• The IP address of a
computer usually consists of
a network, and a host part
that represents a particular
computer on a particular
network.
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2003
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