CCNA 1 and 2 Companion Guide, Revised (Cisco Networking Academy Program) part 5 pps

■ Network interface card NIC—A printed circuit board that provides network communication capabilities to and from a PC.. NOTE Some computers have a network card, sound card, video car

Figure 1-3 Motherboard

■ Read-only memory (ROM)—A type of computer memory in which data has

been prerecorded After data has been written onto a ROM chip, it cannot be removed and can only be read A version of ROM known as EEPROM (electron-ically erasable programmable read-only memory) can be written to It is called Flash memory or firmware The basic input/output system (BIOS) in most PCs is stored in EEPROM

■ Expansion slot—An opening in a computer, usually on the motherboard, where

an expansion card can be inserted to add new capabilities to the computer (see Figure 1-4)

■ System unit—The main component of the PC system It includes the case, chassis,

power supply, microprocessor, main memory, bus, expansion cards, disk drives (floppy, CD hard disk, and so on), and ports The system unit does not include the keyboard, the monitor, or any other external devices connected to the computer

■ Power supply—Supplies power to a computer

Figure 1-4 Expansion Slot

Motherboard Components

The motherboard is the computer’s main circuit board It is crucial because it is the nerve center of the computer system Everything else in the system plugs into it, is con-trolled by it, and depends on it to communicate with other devices in the system The following list describes the motherboard’s various components:

■ Backplane—A large circuit board that contains sockets for expansion cards

■ Memory chips—RAM chips on memory cards plug into the motherboard

■ Network interface card (NIC)—A printed circuit board that provides network communication capabilities to and from a PC Many newer desktop and laptop computers have an Ethernet NIC built into the motherboard

■ Video card—A board that plugs into a PC to give it display capabilities Video cards typically include onboard microprocessors and additional memory to speed up and enhance graphics display

■ Sound card—An expansion board that handles all sound functions

■ Parallel port—An interface that can transfer more than 1 bit at a time It is used

to connect external devices, such as printers

■ Serial port—An interface used for serial communication in which only 1 bit is transmitted at a time The serial port can connect to an external modem, plotter,

or serial printer It can also be used to connect to networking devices such as routers and switches as a console connection

■ Mouse port—Connects a mouse to a PC

■ Keyboard port—Connects a keyboard to a PC

NOTE

Some computers have

a network card,

sound card, video

card, and other cards

integrated into the

motherboard.

■ Power cord—Connects an electrical device to an electrical outlet to provide

power to the device

■ Universal Serial Bus (USB) port—This interface lets peripheral devices such as

mice, modems, keyboards, scanners, and printers be plugged in and unplugged without resetting the system USB ports eventually might replace serial and paral-lel ports

Desktop Versus Laptop

Laptop and notebook computers are becoming increasingly popular The main

differ-ence between desktop PCs and laptops, other than the fact that laptop components are

smaller than those found in a PC, is that laptops offer more mobility and portability

than desktop PCs The expansion slots are called Personal Computer Memory Card

International Association (PCMCIA) card slots or PC card slots in laptop computers

The PC card slots are where devices such as NICs, modems, hard drives, and other

useful devices (usually the size of a thick credit card) are connected Figure 1-5 shows

a PC card adapter for a wireless local-area network (WLAN)

Figure 1-5 PC Card

Lab Activity PC Hardware

This lab helps you become familiar with the basic peripheral components of a

PC system and their connections, including network attachment You examine the internal PC configuration and identify major components You also observe the boot process for the Windows operating system and use the Control Panel

to find out information about the PC hardware

Network Interface Cards

As shown in Figure 1-6, a NIC is a printed circuit board that provides network com-munication capabilities to and from a PC Also called a LAN adapter, a NIC plugs into

a motherboard and provides a port for connecting to the network The NIC consti-tutes the computer interface with the LAN

Figure 1-6 Network Interface Card

The NIC communicates with the network through a cable and with the computer via an expansion slot When a NIC is installed in a computer, it requires an interrupt request (IRQ) for service from the CPU, as well as an input/output (I/O) address, a memory space for the operating system (such as Linux or Windows), and drivers to perform its function An IRQ is a signal that informs a CPU that an event needing its attention has occurred An IRQ is sent over a hardware line to the microprocessor An example of an interrupt being issued is a key being pressed on the keyboard The CPU must move the character from the keyboard to RAM An I/O address is a location in memory used to enter data into or retrieve data from a computer using an auxiliary device

When selecting a NIC for a network, consider the following:

■ Type of network—Different types of networks use different types of NICs For

example, Ethernet NICs are designed for Ethernet LANs Some other types of networks include Token Ring and Fiber Distributed Data Interface (FDDI) Ethernet is by far the most common

■ Type of medium—The type of port or connector used by the NIC for network

connection is specific to the medium type, such as twisted-pair, coaxial, fiber-optic, or wireless Coaxial is becoming increasingly rare

■ Type of system bus—There are different types of system buses, such as PCI and

ISA Because PCI slots are faster than ISA slots, the latter are being phased out

NIC and Modem Installation

Connectivity to the Internet requires an adapter card, which might be a modem or NIC

Amodem is an electronic device that is used for computer communications through

telephone lines It allows data transfer between one computer and another over the

Public Switched Telephone Network (PSTN) Figure 1-7 shows an example of an

external modem Typically, modems send data in blocks of bytes After each block,

basic math is performed to analyze the block, and the computer on the receiving end is

asked whether it agrees with the results If any differences appear, the block is sent

again The modems convert digital data to analog signals for transmission over the

PSTN and then convert analog signals back to digital data on the receiving end

Figure 1-7 External Modem

The term modem derives from the function of this device The process of converting

digital signals to analog and back again is called modulation/demodulation (hence the

term modem) Modems can be installed internally or attached to the computer via a

serial or USB interface externally Modems connect a computer to the network by

dial-ing the telephone number of another computer’s modem, typically that of the Internet

service provider (ISP)

The NIC lets hosts connect to the network The NIC is considered a key component

NICs are available in different types, depending on the individual device configuration

Notebook computers can have a built-in interface or use a PCMCIA card Desktop

systems can use a built-in or adapter card-type NIC

Situations that require NIC installation include the following:

■ Adding a NIC to a PC that does not already have one

■ Replacing a bad or damaged NIC

■ Upgrading from a 10-megabits per second (Mbps) NIC to a 10/100-Mbps NIC

To install a NIC, as shown in Figure 1-8, you need the following resources:

■ Knowledge of how the adapter is configured, including jumpers and plug-and-play software Most modern NICs do not require jumpers and are plug-and-play, requiring little or no configuration They can be configured using software that comes with the NIC if necessary

■ Use of network card diagnostics, including the vendor-supplied diagnostics and loopback test (see the card’s documentation)

■ The ability to resolve hardware resource conflicts, including IRQ, I/O base address, and direct memory address (DMA), which is used to transfer data from RAM to a device without going through the CPU

Figure 1-8 Installing a NIC

Overview of High-Speed and Dialup Connectivity

In the early 1960s, modems were introduced to provide data communications connec-tivity for dumb terminals to a centrally based computer Many companies rented com-puter time because owning an onsite system was cost-prohibitive The connection rate was very slow—300 bits per second (bps), which translates to about 30 characters per second

As PCs became affordable in the 1970s, Bulletin Board Systems (BBSs) appeared, allowing users to connect and post or read messages on a discussion board Running at

300 bps was acceptable, because this exceeds the speed at which most people can read

or type BBSs did not become widely used until the early 1980s, and the transfer of

files and graphics began to be desirable The 300 bps speed quickly became intolerable,

and modem speeds started to increase By the 1990s, modems were running at 9600

bps They reached the current standard of 56 kbps (56,000 bps) by 1998

Inevitably, the high-speed services used in the corporate environment, such as digital

subscriber line (DSL) and cable modem access, migrated to the consumer market

These services no longer required expensive equipment or a second phone line They

are also always-on services and therefore provide instant access that does not require a

connection to be established for each session This results in greater reliability and

flex-ibility It has also led to the ease of Internet connection sharing and small office and

home networks

TCP/IP Configuration

TCP/IP is a set of protocols or rules developed to allow cooperating computers to

share resources across a network A computer must be running the TCP/IP protocol

suite to access the Internet To enable TCP/IP on the workstation, it must be

config-ured using the operating system tools The PC requires an IP address, subnet mask,

default gateway, DNS (domain name server) information These can be assigned

man-ually or obtained from a Dynamic Host Configuration Protocol (DHCP) server The

information necessary to configure TCP/IP on a computer is typically obtained from

a network administrator or an ISP The process is similar whether you’re using a

Windows or Apple Macintosh operating system TCP/IP, DHCP, and DNS are covered

in subsequent chapters

Testing Connectivity with Ping

Pingis a program that is useful for verifying a successful TCP/IP installation It is named

after the sonar operation used to locate and determine the distance to an underwater

object Ping stands for Packet Internet Groper

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, you can

Lab Activity PC TCP/IP Network Settings

This lab introduces you to the methods of discovering your computer’s net-work connection, host name, MAC (Layer 2) address, and netnet-work (Layer 3) address

determine if there is connectivity to a destination The ping command is used to test

the NIC transmit/receive function, the TCP/IP configuration, and network connectivity

The following are some usages of the ping command:

■ ping 127.0.0.1 (internal loopback test)—This verifies the operation of the TCP/IP stack and NIC transmit/receive function Figure 1-9 shows the ping 127.0.0.1 test.

■ ping IP address of host computer—Verifies the TCP/IP address configuration for

the local host

■ ping default-gateway IP address—Verifies whether the router that connects the

local network to other networks can be accessed

■ ping remote destination IP address—Verifies connectivity to a remote host.

Figure 1-9 ping 127.0.0.1

Web Browsers and Plug-Ins

A web browser acts on a user’s behalf by

■ Contacting a web server

■ Requesting information

■ Receiving information

■ Displaying the results on the screen

Lab Activity Using ping and tracert

In this lab, you learn to use the TCP/IP ping and traceroute commands to test

connectivity in a network In the process, you see name resolution occur

A web browser is software that interprets Hypertext Markup Language (HTML), one

of the languages used to code web page content Other markup languages, such as

SGML and XML, provide more advanced features for creating dynamic and

interac-tive web pages than does HTML HTML, the most common markup language, can

display graphics and play sound, movies, and other multimedia files Hyperlinks are

computer program commands that point to other HTML files on a web server or other

places in the same documents, which provide shortcuts to other web pages and files

Two of the most popular web browsers are Internet Explorer (IE) and Netscape Although

they are identical in the task they perform, there are differences between them Some

websites might not support the use of one or the other, so it can be beneficial to have

both programs installed on the computer

Table 1-1 compares the characteristics of these two web browsers

Standard web browsers cannot display many special, or proprietary, file types To view

these files, the browser must be configured to use plug-in applications These

applica-tions work in conjunction with the browser to launch the program required to view

the special files Here are some of the more popular proprietary plug-ins:

■ Flash Player/Shockwave Player—A plug-in that plays multimedia files created by

Macromedia Flash

■ Adobe Acrobat Reader—A software program that allows the user to view and

print Adobe Portable Document Format (PDF) files

■ Windows Media Player—A software program that allows the user to play audio

and video files

■ Quicktime—A software program created by Apple that allows the user to play

video and audio files

■ Real Player—A software program that allows the user to play audio files.

Table 1-1 Microsoft Internet Explorer Versus Netscape Communicator

Integrated with other Microsoft products First popular browser

Takes up more disk space Takes up less disk space

Displays HTML files and performs e-mail,

file transfers, and other functions

Displays HTML files and performs e-mail, file transfers, and other functions

Other Common Computer Applications

Computers perform many other useful tasks In business, employees regularly use a set

of applications that come in the form of an office suite, such as Microsoft Office or

Lotus Smart Suite Office applications typically include the following:

■ Spreadsheet software—An application that lets users construct spreadsheets

consisting of columns and rows It is often used with formulas to process and analyze data

■ A word processor—An application that lets users create and edit text documents

Modern word processors allow the user to create sophisticated documents that include graphics and richly formatted text

■ Database software—An application that lets users store, maintain, organize, sort,

and filter records A record is a collection of information identified by a common

theme, such as a customer name

■ Presentation software—An application that lets users design and develop

presen-tations to deliver at meetings, classes, or sales presenpresen-tations

■ Personal information managers—Applications that can include features such as

e-mail, contact lists, a calendar, and a to-do list

Binary Numbers

This section introduces the way in which data is represented inside a computer and the form in which it is transmitted across a network You also learn about the various number systems and logic used with computers

Lab Activity Web Browser Basics

In this lab, you learn how to use a web browser to access Internet sites, become familiar with the concept of a URL, and use a search engine to locate informa-tion on the Internet You access selected websites to learn the definiinforma-tions of net-working terms and use hyperlinks to jump from the current website to other websites

Lab Activity The Basic PC/Network Troubleshooting Process

In this lab, you apply the basic troubleshooting model to simple and common network problems You also become familiar with the more common hard-ware and softhard-ware problems