Transcript Chapter 1

CCNA
CISCO CERTIFIED
NETWORK ASSOCIATE
Main Objectives
Understand the physical connection that has to
take place for a computer to connect to the
Internet.
Recognize the components that comprise the
computer.
Install and troubleshoot network interface cards
and/or modems.
Use basic testing procedures to test the Internet
connection.
Demonstrate a basic understanding of the use
of web browsers and plug-ins
Computer Basics
Small, Discrete
Components
Personal Computer
Subsystems
Backplane
Components
Electronic Components
Capacitor
 stores energy in the form of an
electrostatic field
Connector
 the part of a cable that plugs
into a port or an interface
Integrated circuit (IC)
 a device made of semiconductor material;
it contains many transistors and performs
a specific task
Electronic Components
Light emitting diode
a semiconductor device that
emits light when a current
passes through it
Resistor
a device made of a material that
opposes the flow of electric
current
Transistor
a device that amplifies a signal
or opens and closes a circuit
Personal Computer Subsystems
Bus
 collection of wires through which data is
transmitted from one part of the computer to
another; connects all the internal computer
components to the CPU (ISA and PCI)
CD-ROM drive
 a compact disk read-only memory drive; a device
that can read information from a CD-ROM
Central processing unit (CPU)
 the brains of the computer where most
calculations take place
Personal Computer Subsystems
Expansion card
 a printed circuit board you can insert into a
computer to give it added capabilities
Expansion slot
 an opening in a computer where a
circuit board can be added
Floppy disk drive
 a disk drive that can read or write to floppy disks
Hard disk drive
 a device that reads and writes data on a hard disk
Personal Computer Subsystems
Microprocessor
 a silicon chip that contains a CPU
Motherboard
 the main printed circuit board of a microprocessor
Power supply
 the component that supplies the power to a
computer
Printed circuit board (PCB)
 a thin plate on which chips (ICs) and other
electronic components are placed
Personal Computer Subsystems
Random access memory (RAM)
 RAM can have new data written into it and stored
data read from it; a drawback of RAM is that it
requires electrical power to maintain data storage
Read-only memory (ROM)
 computer memory on which data has
been prerecorded
System unit
 the main part of a PC; the system unit includes the
chassis, the microprocessor, the main memory, the
bus, and the ports
Hard drive interfaces
interface is the way the drive
communicates with the computer; a
sort of language that allows the drive
and the computer to talk to each other
IDE, SCSI
most controller circuitry is placed directly on
the hard drive
Modems
 modem converts digital data from its
local computer into analog tones and
pulses that can be sent over the
telephone lines
 two basic types--internal/external
The Power Supply
 converts AC from wall outlet to DC
used by computers
 contains fan and AC/DC converter
Backplane Components
Backplane
the large circuit board that
contains slots for expansion cards
Interface
a piece of hardware such as a
modem connector that allows two
devices to be connected
Mouse port
a port designed to connect a
mouse to a PC
Backplane Components
Network card
an expansion board inserted into a computer so
that the computer can be connected to a
network
Parallel port
an interface capable of transferring more than
one bit simultaneously; used to connect external
devices such as printers
Port
an interface on a computer to which you can
connect an electronic device
Backplane Components
Power cord
 a cord used to connect computer to electrical
outlet
Serial port
 an interface that can be used for serial communication in which only one bit is transmitted at a
time
Sound card
 an expansion card that handles all sound functions
Video card
 a board that plugs into a PC to give it display
capabilities
Information Flow
Information and electric power are constantly
flowing in a PC.
 Boot instructions—stored in ROM until they are sent out
 Software applications—stored in RAM after they are loaded
 RAM and ROM—constantly talk to the CPU through the
bus
 Application information—stored in RAM
while applications are being used
 Saved information—flows from RAM to
some form of storage device
 Exported information—flows from RAM
and the CPU through the bus and
expansion slots to the printer, the video card, the sound
card, or the network card
An Idealized Computer
What’s in that box?
Inside a Computer
An Idealized Computer:
Information Flow
Network Interface Cards
printed circuit board
that provides network
capability to
computer
also called a LAN
adapter
can be designed as
an Ethernet, Token
Ring, or FDDI card
Network Interface Cards
communicate through a serial
connection
Each card requires an IRQ, an
I/O address, and an upper
memory address to work with
DOS/WIN95.
To configure TCP/IP LAN settings
in a Windows machine, use the
Control Panel icon, Network.
Network Interface Cards
Considerations:
 type of network (Ethernet,
Token Ring, FDDI)
 type of media (CAT5, fiber,
wireless)
 type of system bus either
PCI/ISA or PCMCIA, which is
used on laptops)
 To change a PCs network speed
from 10Mbps to 100Mbps, you
need to upgrade the NIC.
TCP/IP
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. The process is
very similar whether using a Windows or
Mac operating system.
TESTING CONNECTIVITY

The ping command works by sending multiple IP
packets to a specified destination. Each packet sent is a
request for a reply. The output response for a ping
contains the success ratio and round-trip time to the
destination. From this information, it is possible to
determine if there is connectivity to a destination.
 ping 127.0.0.1
 Ping 195.14.130.220
Web Browsers
Plug-ins allow the browser to display proprietary file types.
Plug Ins
Flash/Shockwave
Troubleshooting Internet
connection problems
Define the problem
Gather the facts
Consider the possibility
Create action plan
Implement plan
Observe results
Document results
Binary Number System
 Computer systems only
understand “on” and
“off” or “1s” and “0s.”
27 26 25 24 23 22 21 20
 Computer systems use
a binary numbering
128 64 32 16
8
4
2
1
system rather than
decimal.
 Decimal numbering
8 bits = 1 byte
system uses 10
symbols; they are 0-9.
A bit is a binary digit used
 Computer systems use
in the binary numbering
a Base 2 system.
system, either 0 or 1.
Binary Number System
Binary Number System
The binary number 10010001 in Base 2 =
145.
27
26
25
24
23
22
21
20
128
64
32
16
8
4
2
1
1
0
0
1
0
0
0
1
(1, 128) = 128 + (0, 64) =
0 + (0, 32) = 0 + (1, 16) = 16
+ (0, 8) = 0 + (0, 4) = 0 + (0, 2) = 0 + (1, 1) = 1 = 145
Binary Number System
The decimal number 35 in Base 2
27
26
25
24
23
22
21
20
128
64
32
16
8
4
2
1
0
0
1
0
0
0
1
1
Binary Number System
If the right-most digit is odd, then the
number is odd. (255)
27
26
25
24
23
22
21
20
128
64
32
16
8
4
2
1
1
1
1
1
1
1
1
1
Binary Number System
If the right-most digit is even, then the
number is even. (142)
27
26
25
24
23
22
21
20
128
64
32
16
8
4
2
1
1
0
0
0
1
1
1
0