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An Introduction to NetworkingAn Introduction to Networking

After reading this chapter and completing theexercises, you will be able to:

• List the advantages of networked computing relative to stand-alone computing

• Distinguish between client/server and peer-to-peer networks

• List elements common to all client/server networks

• Describe several specific uses for a network

• Identify some of the certifications available to networkingprofessionals

• Identify the kinds of skills and specializations that will help youexcel as a networking professional

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Loosely defined, a network is a group of computers and other devices (such as printers) thatare connected by some type of transmission media. Variations on the elements of a networkand the way it is designed, however, are nearly infinite. Networks can be as small as twocomputers connected by a cable in a home office or as large as several thousand computersconnected across the world via a combination of cable, phone lines, and satellite links. Inaddition to connecting personal computers, networks might link mainframe computers,printers, plotters, fax machines, and phone systems. They might communicate throughcopper wires, fiber-optic cable, radio waves, infrared, or satellite links. This chapter intro-duces you to the fundamental characteristics of networks.

Why Use Networks?Using networks offers advantages relative to using a stand-alone computer—that is, a com-puter that is not connected to other computers and that uses software applications and datastored on its local disks. Most importantly, networks enable multiple users to share devices(for example, printers) and data (such as spreadsheet files), which are collectively known asthe network’s resources. Sharing devices saves money. For example, rather than buying20 printers for 20 staff members, a company can buy one printer and have those 20 staffmembers share it over a network. Sharing devices also saves time. For example, it’s faster forcoworkers to share data over a network than to copy data to a removable storage deviceand physically transport the storage device from one computer to another—an outdated file-sharing method commonly referred to as sneakernet (presumably because people woresneakers when walking from computer to computer). Before networks, transferring data viafloppy disks was the only possible way to share data.

My job as a recruiter is to match a candidate with a position that matches his or her skillsand career goals. One time a newgraduate came tome looking forwork in the network-ing field. Although he had no previous networking experience, I was able to find him aposition by emphasizing the hands-on experience he had gained in college networkingcourses. To help him lookmore appealing to employers, I reworded his resume and spec-ified the software and hardware he used in his hands-on projects. I also asked him to tellme about technical obstacles he had overcome and what he had learned from the pro-jects. Soon, my client found an assignment as a technical support specialist at a largepharmaceutical firm. Now, five years later, he is a network administrator for one of thecountry’s largest banks. Although my client had little experience in the beginning, hisalways-positive attitude and a willingness to learn helped him advance quickly.

Tracy Syslo, RecruiterInfostaff Services Corporation

On the JobOn the Job

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11Networks also allow you to manage, or administer, resources on multiple computers from acentral location. Imagine you work in the Information Technology (IT) department of a multi-national bank and must verify that each of 5000 employees around the globe uses the sameversion of a database program. Without a network, you would have to visit every employee’smachine to check and install the proper software. With a network, however, you could checkthe software installed on computers around the world from the computer on your desk.Because they allow you to share devices and administer computers centrally, networksincrease productivity. It’s not surprising, then, that virtually all organizations depend on theirnetworks to stay competitive.

Types of NetworksComputers can be positioned on a network in different ways relative to each other. They canhave different levels of control over shared resources. They can also be made to communicateand share resources according to different schemes. The following sections describe twofundamental network models: peer-to-peer and client/server.

Peer-to-Peer NetworksThe simplest form of a network is a peer-to-peer network. In a peer-to-peer network, everycomputer can communicate directly with every other computer. By default, no computer on apeer-to-peer network has more authority than another. However, each computer can be con-figured to share only some of its resources and prevent access to other resources. Traditionalpeer-to-peer networks typically consist of two or more general-purpose personal computers,with modest processing capabilities. Every computer is capable of sending and receivinginformation to and from every other computer, as shown in Figure 1-1.

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Figure 1-1 Resource sharing on a simple peer-to-peer network

Types of Networks 3

The following are advantages of using traditional peer-to-peer networks:

• They are simple to configure. For this reason, they may be used in environments inwhich time or technical expertise is scarce.

• They are often less expensive to set up and maintain than other types of networks.This fact makes them suitable for environments in which saving money is critical.

The following are disadvantages of using traditional peer-to-peer networks:

• They are not very flexible. As a peer-to-peer network grows larger, adding or changingsignificant elements of the network may be difficult.

• They are also not necessarily secure—meaning that in simple installations, data andother resources shared by network users can be easily discovered and used by unautho-rized people.

• They are not practical for connecting more than a handful of computers, because theydo not always centralize resources.

For example, if your computer is part of a peer-to-peer network that includes five other com-puters, and each computer user stores her spreadsheets and word-processing files on her ownhard disk, whenever your colleagues want to edit your files, they must access your machineon the network. If one colleague saves a changed version of one of your spreadsheets on herhard disk, you’ll find it difficult to keep track of which version is the most current. As youcan imagine, the more computers you add to a peer-to-peer network, the more difficult itbecomes to find and manage resources.

A common way to share resources on a peer-to-peer network is by modifying the file-sharingcontrols via the computer’s operating system. For example, you could choose to create adirectory on your computer’s hard disk called “SharedDocs” and then configure the directoryto allow all networked computers to read its files. On a peer-to-peer network, each user isresponsible for configuring her computer to allow access to certain resources and preventaccess to others. In other words, resource sharing is not controlled by a central computer orauthority. Because access depends on many different users, it might not be uniform or secure.

Although traditional peer-to-peer networks are typically small and contained within a homeor office, examples of very large peer-to-peer networks have emerged to take advantage ofthe Internet. These newer types of peer-to-peer networks (commonly abbreviated P2P net-works) link computers from around the world to share files between each others’ harddisks. Unlike the older style of peer-to-peer network, they require specialized software(besides the computer’s operating system) to allow resource sharing. Examples of these net-works include Gnutella, Freenet, and the original Napster. In 2001, Napster, which allowedusers around the globe to share music files, was forced to cease operation due to chargesof copyright infringement from musicians and music producers. Later, the service wasredesigned to provide legitimate music file-sharing services. More recently, a company calledBitTorrent has made a unique high-speed data transfer technology (also called BitTorrent) thefoundation of its business. The company specializes in allowing companies and individuals toshare video, audio, software, and games over the Internet.

Client/Server NetworksAnother way of designing a network is to use a central computer, known as a server, to facil-itate communication and resource sharing between other computers on the network, which

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11are known as clients. Clients usually take the form of personal computers, also known asworkstations. A network that uses a server to enable clients to share data, data storagespace, and devices is known as a client/server network. (The term client/server architectureis sometimes used to refer to the design of a network in which clients rely on servers forresource sharing and processing.) In terms of resource sharing and control, you can comparethe client/server network to a public library. Just as a librarian manages the use of books andother media by patrons, a server manages the use of shared resources by clients. For example,if a patron does not have the credentials to check out books, the librarian prevents the patronfrom doing so. Similarly, a server allows only authorized clients to access its resources.

Every computer on a client/server network acts as a client or a server. (It is possible, butuncommon, for some computers to act as both.) Clients on a network can still run applica-tions from and save data to their local hard disk. But by connecting to a server, they alsohave the option of using shared applications, data, and devices. Clients on a client/server net-work do not share their resources directly with each other, but rather use the server as anintermediary. Clients and servers communicate through connectivity devices such as switchesor routers. (These devices are covered in detail in Chapter 6.)

Figure 1-2 illustrates how resources are shared on a client/server network.

To function as a server, a computer must be running an NOS (network operating system).An NOS is a special type of software designed to do the following:

• Manage data and other resources for a number of clients.

• Ensure that only authorized users access the network.

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Types of Networks 5

• Control which type of files a user can open and read.

• Restrict when and from where users can access the network.

• Dictate which rules computers will use to communicate.

• Supply applications to clients.

Examples of popular network operating systems include various forms of UNIX and Linux,Microsoft Windows Server 2003 or Server 2008, and Mac OS X Server. (By contrast, astand-alone computer, or a client computer, uses an operating system, such as Windows XPor Windows Vista, which has more limited resource management capabilities.)

Usually, servers have more memory, processing, and storage capacity than clients. They mayeven be equipped with special hardware designed to provide network management functionsbeyond that provided by the network operating system. For example, a server might containan extra hard disk and specialized software so that if the primary hard disk fails, the second-ary hard disk automatically takes its place.

Although client/server networks are typically more complex in their design and mainte-nance than peer-to-peer networks, they offer many advantages over peer-to-peer networks,such as:

• User logon accounts and passwords for anyone on a server-based network can beassigned in one place.

• Access to multiple shared resources (such as data files or printers) can be centrallygranted to a single user or groups of users.

• Problems on the network can be monitored, diagnosed, and often fixed from onelocation.

• Servers are optimized to handle heavy processing loads and dedicated to handlingrequests from clients, enabling faster response time.

• Because of their efficient processing and larger disk storage, servers can connect morethan a handful of computers on a network.

Together, these advantages make client/server networks easier to manage, more secure, andmore powerful than peer-to-peer networks. They are also more scalable—that is, they canbe more easily added onto and extended—than peer-to-peer networks.

Because client/server networks are the most popular type of network for medium- and large-scale organizations, most of the concepts covered in this book and on the Network+ exampertain to client/server networks. Next, you will learn how networks are classified accordingto size.

LANs, MANs, and WANsAs its name suggests, a LAN (local area network) is a network of computers and otherdevices that is confined to a relatively small space, such as one building or even one office.Small LANs first became popular in the early 1980s. At that time, LANs might have con-sisted of a handful of computers connected in a peer-to-peer fashion. Today’s LANs are typi-cally much larger and more complex client/server networks.

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11Often, separate LANs are interconnected and rely on several servers running many differentapplications and managing resources other than data. For example, imagine an office build-ing in which each of a company’s departments runs its own LAN and all the LANs areconnected. This network may contain dozens of servers, hundreds of workstations, and sev-eral shared storage devices, printers, plotters, fax machines, and even telephone interfaces.Figure 1-3 roughly depicts this type of network (in reality, the network would probably con-tain many more clients). As you progress through this book, you will learn about the deviceson this network and how they communicate. After completing this book you’ll understandhow to integrate clients, servers, and connectivity devices so as to create networks that arereliable, secure, and manageable.

Networks may extend beyond the boundaries of a building. A network that is larger than aLAN and connects clients and servers from multiple buildings—for example, a handful ofgovernment offices surrounding a state capitol—is known as a MAN (metropolitan area net-work). Because of the distance it covers, a MAN may use different transmission technologyand media than a LAN.

A network that connects two or more geographically distinct LANs or MANs is called aWAN (wide area network). Because such networks carry data over longer distances thanLANs, WANs require slightly different transmission methods and media and often use agreater variety of technologies than LANs. Most MANs can also be described as WANs; infact, network engineers are more likely to refer to all networks that cover a broad geographi-cal range as WANs.

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Types of Networks 7

WANs commonly connect separate offices in the same organization, whether they are acrosstown or across the world from each other. For example, imagine you work for a nationwideplumbing supply company that keeps its inventory in warehouses in Topeka, Kansas, andPanama City, Florida. Suppose also that the company’s headquarters is located in New York.When a customer calls and asks whether you have 5 faucets of a certain type available to shipovernight, you need to check the inventory databases for both the Topeka and Panama Citywarehouses. Thanks to your WAN, the data is accessible from your New York desktop.Twice a day the warehouses’ inventory software automatically updates a database locatedon a central server in New York via WAN links that connect the locations.

WANs are also used to connect LANs that belong to different organizations. For example, allthe public universities within a state might combine and share their resources via a WAN.The largest and most varied WAN in the world is the Internet. Figure 1-4 depicts a simpleWAN.

Elements Common to Client/Server Networks

You have learned that networks—no matter how simple or how complex—provide somebenefits over stand-alone computers. They also share terminology and common buildingblocks, some of which you have already encountered. The following list provides a morecomplete rundown of basic elements common to all client/server networks. You will learnmore about these topics throughout this book:

• Client—A computer on the network that requests resources or services from anothercomputer on a network; in some cases, a client could also act as a server. The termclient may also refer to the human user of a client workstation or to client softwareinstalled on the workstation.

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11• Server—A computer on the network that manages shared resources; servers usually

have more processing power, memory, and hard disk space than clients. They runnetwork operating software that can manage not only data, but also users, groups,security, and applications on the network.

• Workstation—A personal computer (such as a desktop or laptop), which may or maynot be connected to a network; most clients are workstation computers.

• NIC (network interface card)—The device (pronounced nick) inside a computer thatconnects a computer to the network media, thus allowing it to communicate withother computers; many companies (such as 3Com, IBM, Intel, SMC, and Xircom)manufacture NICs, which come with a variety of specifications that are tailored to therequirements of the workstation and the network. Some connect to the motherboard,which is the main circuit that controls the computer, some are integrated as part of themotherboard, and others connect via an external port. NICs are also known as net-work adapters. Figure 1-5 depicts a NIC connected to a computer’s motherboard.

Because different PCs and network types require different kinds ofNICs you cannot assume that a NIC that works in one workstationwill work in another.

• NOS (network operating system)—The software that runs on a server and enables theserver to manage data, users, groups, security, applications, and other networkingfunctions. Examples include various types of UNIX and Linux operating systems,Microsoft Windows Server 2003 or Windows Server 2008, and Mac OS X Server.

• Host—A computer that enables resource sharing by other computers on the samenetwork

• Node—A client, server, or other device that can communicate over a network and thatis identified by a unique number, known as its network address

• Connectivity device—A specialized device that allows multiple networks or multipleparts of one network to connect and exchange data. A client/server network can

Figure 1-5 A NIC (network interface card)

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Elements Common to Client/Server Networks 9

operate without connectivity devices. However, medium- and large-sized LANs usethem to extend the network and to connect with WANs.

• Segment—A part of a network. Usually, a segment is composed of a group of nodesthat use the same communications channel for all their traffic.

• Backbone—The part of a network to which segments and significant shared devices(such as routers, switches, and servers) connect. A backbone is sometimes referred toas “a network of networks,” because of its role in interconnecting smaller parts of aLAN or WAN. Figure 1-6 shows a LAN with its backbone highlighted.

• Topology—The physical layout of a computer network. Topologies vary according tothe needs of the organization and available hardware and expertise. Networks can bearranged in a ring, bus, or star formation, and the star formation is the most com-mon. Hybrid combinations of these patterns are also possible. Figure 1-7 illustratesthese network topologies, which you must understand to design and troubleshootnetworks.

• Protocol—A standard method or format for communication between networkeddevices. Protocols ensure that data are transferred whole, in sequence, and withouterror from one node on the network to another.

• Data packets—The distinct units of data that are exchanged between nodes on a net-work. Breaking a large stream of data into many packets allows a network to deliverthat data more efficiently and reliably.

• Addressing—The scheme for assigning a unique identifying number to every node onthe network. The type of addressing used depends on the network’s protocols and net-work operating system. Each network device must have a unique address so that datacan be transmitted reliably to and from that device.

• Transmission media—The means through which data is transmitted and received.Transmission media may be physical, such as wire or cable, or atmospheric (wireless),such as radio waves. Figure 1-8 shows several examples of transmission media.

Now that you are familiar with basic network terminology, you are ready to appreciate themany uses of computer networks.

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Ring Hybrid

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Figure 1-7 Common network topologies

Radio waves

Coaxial cabl

Fiber-optic cable

Shielded twisted-pair cable

Figure 1-8 Examples of network transmission media

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Elements Common to Client/Server Networks 11

How Networks Are UsedThe functions provided by a network are usually referred to as network services. Any net-work manager will tell you that the network service with the highest visibility is e-mail. Ifyour company’s e-mail system fails, users will notice within minutes—and they will not beshy about informing you of the failure. Although e-mail may be the most visible network ser-vice, other services can be just as vital. Printer sharing, file sharing, Internet access and Website delivery, remote access capabilities, the provision of voice (telephone) and video services,and network management are all critical business functions provided through networks. Inlarge organizations, separate servers may be dedicated to performing each of these functions.In offices with only a few users and little network traffic, one server may perform allfunctions.

File and Print ServicesFile services refer to the capability of a server to share data files, applications (such as word-processing or spreadsheet programs), and disk storage space. A server that provides fileservices is called a file server. File services accounted for the first use of networks and remainthe foundation of networking today, for a number of reasons. As mentioned earlier, it is eas-ier and faster to store shared data at a central location than to copy files to disks and thenpass the disks around. Data stored at a central location is typically more secure because anetwork administrator can take charge of backing up this data, rather than relying on indi-vidual users to make their own copies. In addition, using a file server to run applications formultiple users requires the purchase of fewer copies of the application and less maintenancework for the network administrator.

Using print services to share printers across a network also saves time and money. A high-capacity printer can cost thousands of dollars, but can handle the printing tasks of an entiredepartment, thereby eliminating the need to buy a desktop printer for each worker. With oneprinter, less time is spent on maintenance and management. If a shared printer fails, the net-work administrator can diagnose the problem from a workstation anywhere on the networkusing the network operating system’s printer control functions. Often, the administrator cansolve the problem without even visiting the printer.

Access ServicesA network’s access services allow remote users to connect to the network. (The term remoteuser refers to a person working on a computer on a different network or in a different geo-graphical location from the LAN’s server.) Less frequently, access services allow networkusers to connect to machines outside the network. Most network operating systems includebuilt-in access services that enable users to dial in to a remote access server, log on to thenetwork, and take advantage of the network just as if they were logged on to a workstationon the office LAN. A remote access server may also be known as simply an access server.

Organizations commonly use access services to provide LAN connectivity for workers athome, workers on the road, and workers at small satellite offices where dedicated WAN con-nections are not cost-effective. In addition, they may use access services to allow staff fromother organizations (such as a software or hardware vendor) to help diagnose a network

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11problem. For example, suppose you work for a clothing manufacturer that uses embroiderysoftware to control the machines that sew insignias on shirts and hats. You are an expert onnetworking, but less adept with the automated embroidery software. When the softwarecauses problems, you turn to the software vendor for help. But suppose the vendor’s techni-cian can’t solve the problem except by logging on to your network. In that case, it is muchmore efficient and less expensive to allow the technician to dial in to your network througha remote access server than to fly the technician to your office.

It is important to remember that remote access servers—no matter which platform (hardwareor operating system software) they run on—allow external users to use network resourcesand devices just as if they were logged on to a workstation in the office. From a remote loca-tion, users can print files to shared printers, log on to hosts, retrieve mail from an internalmessaging system, or run queries on internal databases. Because they can be accessed by theworld outside the local network, remote access servers necessitate strict security measures.

Communications ServicesToday’s networks can help users communicate in many ways: e-mail, telephone, video, fax,cell phone, and personal digital assistant (for example, a BlackBerry). The phenomenon ofoffering multiple types of communications services on the same network is known as conver-gence. A similar term is unified communications, which refers to the centralized managementof multiple network-based communications. For example, your company might use one soft-ware program to manage intraoffice phone calls, long-distance phone calls, cell phone calls,voice mail, faxes, and text messaging for all the users on your network.

The oldest and still most frequently used network communications services are mail services,which coordinate the storage and transfer of e-mail between users on a network. The com-puter responsible for mail services is called a mail server. Mail servers are usually connectedto the Internet, but when clients only need to exchange e-mail within their organization, theirmail server may be isolated on their LAN.

In addition to simply sending, receiving, and storing mail, mail servers can do the following:

• Intercept or filter unsolicited e-mail, known as spam.

• Find objectionable content in e-mails and perform functions (such as user notification)on that content.

• Route messages according to particular rules—for example, if a technical supportrepresentative has not opened a customer’s message within 15 minutes of delivery,a mail server could automatically forward the message to a supervisor.

• Provide a Web-based client for checking e-mail.

• Notify administrators or users if certain events occur (for example, if a user’s mailboxis close to exceeding its maximum amount of space on a server).

• Schedule e-mail transmission, retrieval, storage, and maintenance functions.

• Communicate with mail servers on other networks so that mail can be exchangedbetween users who do not connect to the same LAN.

To supply these services, a mail server runs specialized mail server software, examples ofwhich include Sendmail and Microsoft Exchange Server. Because of their critical nature and

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heavy use, maintaining a mail server in any sizable organization requires a significant com-mitment of technical support and administration resources.

Internet ServicesYou have probably connected to the Internet without knowing or caring about all of the ser-vices running behind the scenes. But in fact, many servers are working together to bring Webpages to your desktop. For example, a Web server is a computer installed with the appropri-ate software to supply Web pages to many different clients upon demand. Supplying Webpages is only one type of Internet service. Other Internet services include file transfer capabil-ities, Internet addressing schemes, security filters, and a means for directly logging on to othercomputers on the Internet.

Management ServicesWhen networks were small, they could be managed easily by a single network administratorand the network operating system’s internal functions. For instance, suppose a user called toreport a problem logging on to the network and that the administrator diagnosed the prob-lem as an addressing conflict (that is, two workstations having the same network address).In a very small network, the conflicting workstations might be located right around the cor-ner from each other, and one address could be changed quickly. In another example, if amanager needed to report the number of copies of Adobe Photoshop in use in a certaindepartment, the network administrator could probably get the desired information by justwalking through the department and checking the various workstations.

As networks grow larger and more complex, however, they become more difficult to manage.Using network management services can help you keep track of a large network. Networkmanagement services centrally administer management tasks on the network, such as ensur-ing that no more than 20 workstations are using Adobe Photoshop at one time in anorganization that purchased a 20-user license for the software. Some organizations dedicatea number of servers to network management functions, with each server performing onlyone or two unique services.

Numerous services fall under the category of network management. Some of the most impor-tant ones include the following:

• Traffic monitoring and control—Determining how much traffic (that is, data trans-mission activity) is taking place on a network and notifying administrators when thenetwork becomes overloaded. In general, the larger the network, the more critical it isto monitor traffic.

• Load balancing—Distributing data transfer activity evenly across a network so that nosingle device becomes overwhelmed. Load balancing is especially important for net-works in which it’s difficult to predict the number of requests that will be issued to aserver, as is the case with Web servers.

• Hardware diagnosis and failure alert—Determining when a network component failsand automatically notifying the network administrator through e-mail or paging

• Asset management—Collecting and storing data on the number and types of softwareand hardware assets in an organization’s network. With asset management software,a server can electronically examine each client’s software and hardware and automatically

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11save the data in a database. Other types of assets might be might be identified andtracked using RFID (radio frequency identification) tags, which emit a wireless signalat all times. Wireless detection devices connected to a network can track the locationsof RFID-tagged devices. For example, a hospital might use RFID tags to keep track ofthe wheelchairs, beds, and IV pumps that circulate throughout its campus. Before assetmanagement services, inventory data had to be gathered manually and typed intospreadsheets.

• License tracking—Determining how many copies of a single application are currentlyin use on the network and ensuring that number does not exceed the number oflicenses purchased. This information is important for legal reasons, as software com-panies are vigilant about illegally copying software or using more than the authorizednumber of copies.

• Security auditing—Evaluating what security measures are currently in force and noti-fying the network administrator if a security breach occurs.

• Software distribution—Automatically transferring a file or installing an applicationfrom the server to a client on the network. The installation process can be started fromeither the server or the client. Several options are available when distributing software,such as warning users about updates, writing changes to a workstation’s system files,and restarting the workstation after the update.

• Address management—Centrally managing a finite number of network addresses foran entire network. Usually this task can be accomplished without manually modifyingthe client workstation configurations.

• Backup and restoration of data—Copying (or backing up) critical data files to asecure storage area and then restoring (or retrieving) data if the original files are lost ordeleted. Often backups are performed according to a formulaic schedule. Backup anddata restoration services provide centralized management of data backup on multipleservers and on-demand restoration of files and directories.

Network management services will be covered in depth later in the book. For now, it isenough to be aware of the variety of services and the importance of this growing area ofnetworking.

Becoming a Networking ProfessionalIf you search online employment services, you’ll probably find hundreds of postings for com-puter professionals. Of course, the level of expertise required for each of these jobs differs.Some companies simply need “warm bodies” to ensure that a higher-level engineer is notifiedif a critical network segment fails; other companies are looking for people to plan their globalinformation technology strategies. Needless to say, the more extensive your skills, the betteryour chances for landing a lucrative and interesting job in networking. To prepare yourselfto enter this job market, master a number of general networking technologies. Only thenshould you pick a few areas that interest you and study those specialties. Hone your commu-nication and teamwork skills, and stay abreast of emerging technologies. Consider the tremen-dous advantages of attaining professional certification and getting to know others in yourfield. The following sections offer suggestions on how to approach a career in networking.

Becoming a Networking Professional 15

Mastering the Technical ChallengesAlthough computer networking is a varied field, some general technical skills will serve youwell no matter which specialty you choose. Because you are already interested in computers,you probably enjoy an aptitude for logical and analytical thinking. You probably also wantto acquire these skills:

• Installing, configuring, and troubleshooting network server software and hardware

• Installing, configuring, and troubleshooting network client software and hardware

• Understanding the characteristics of different transmission media

• Understanding network design

• Understanding network protocols

• Understanding how users interact with the network

• Constructing a network with clients, servers, media, and connectivity devices

Because you can expand your networking knowledge in almost any direction, you shouldpay attention to the general skills that interest you most, then pick one or two of thoseareas and concentrate on them. The following specialties are currently in high demand:

• Network security

• Convergence (the delivery of voice, video, and data over a single network)

• In-depth knowledge about one or more NOSs: UNIX, Linux, Mac OS X Server,Microsoft Windows Server 2003, or Windows Server 2008

• Network management

• Internet and intranet design

• Configuration and optimization of routers and switches

• Centralized data storage and management for large-scale environments

Determine which method of learning works best for you. A small classroom with an experi-enced instructor and a hands-on projects lab is an excellent learning environment, becausethere you can ask questions and learn by doing. Many colleges offer courses or continuingeducation on networking topics. You may also want to enroll at a computer training center.These training centers can be found in every metropolitan area and in many small towns. Ifyou are pursuing certification, be certain the training center you choose is authorized to pro-vide training for that certification. Most computer training centers also operate a Web sitethat provides information on their course schedule, fees, and qualifications. Some of thesesites even offer online class registration.

There is no substitute for hands-on experience when it comes to improving your networkinghardware and software skills. If you don’t already work in an IT department, try to find aposition that puts you in that environment, even if it isn’t your dream job. Volunteer a fewhours a week if necessary. After you are surrounded with other information technology pro-fessionals and encounter real-life situations, you will have the opportunity to expand yourskills by practicing and asking questions of more experienced staff. On the Web, you canfind a number of searchable online job boards and recruiter sites. The placement office atyour local college or university can also connect you with job opportunities.

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11Developing Your “Soft Skills”Knowing how to configure a router or install UNIX will serve you well, but advanced softskills will help you stand out. The term soft skills refers to those skills that are not easilymeasurable, such as customer relations, oral and written communications, dependability,teamwork, and leadership abilities. Some of these soft skills might appear to be advantagesin any profession, but they are especially important when you must work in teams, in chal-lenging technical circumstances, and under tight deadlines—requirements that apply to mostnetworking projects. For this reason, soft skills merit closer examination:

• Customer relations—Perhaps one of the most important soft skills, customer rela-tions involve an ability to listen to customers’ frustrations and desires and thenempathize, respond, and guide customers to their goals without acting arrogant.Bear in mind that some of your customers will not appreciate or enjoy technology asmuch as you do, and they will value your patience as you help them. The betteryour customer relations, the more respected and in demand you will be as a networkprofessional.

• Oral and written communications—You may understand the most complicated tech-nical details about a network, but if you cannot communicate them to colleaguesand clients, the significance of your knowledge is diminished. Imagine that you are anetworking consultant who is competing with several other firms to overhaul ametropolitan hospital’s network, a project that could generate millions of dollars foryour company. You may have designed the best solution and have it clearly mappedout in your head, but your plan is useless if you can’t describe it clearly. The hos-pital’s planning committee will accept whichever proposal makes the most senseto them—that is, the proposal whose suggestions and justifications are plainlycommunicated.

• Dependability—This characteristic will help you in any career. However, in the field ofnetworking, where breakdowns or glitches can occur at any time of day or night andonly a limited number of individuals have the expertise to fix them, being dependableis critical. Your career will benefit when you are the one who is available to address aproblem, even if you don’t always know the answer immediately.

• Teamwork—Individual computer professionals often have strong preferences for acertain type of hardware or software. Some technical people like to think that theyhave all of the answers. For these and other reasons, teamwork in IT departments issometimes lacking. To be the best networking professional in your department, youmust be open to new ideas, encourage cooperation among your colleagues, and allowothers to help you and make suggestions.

• Leadership abilities—As a networking professional, you will sometimes need to makedifficult or unpopular decisions under pressure. You may need to persuade opinionatedcolleagues to try a new product, tell a group of angry users that what they want is notpossible, or manage a project with nearly impossible budgetary and time restrictions.In all of these situations, you will benefit from having strong leadership skills.

After your career in networking begins, you will discover which soft skills you already pos-sess and which ones you need to cultivate. The important thing is that you realize the impor-tance of these attributes and are willing to devote the time necessary to develop them.


Pursuing CertificationCertification is the process of mastering material pertaining to a particular hardware system,operating system, programming language, or software application, then proving your mas-tery by passing a series of exams. Certification programs are developed and administeredeither by a manufacturer or a professional organization such as CompTIA (ComputingTechnology Industry Association). You can pursue a number of different certifications,depending on your specialty interest. For example, if you want to become a PC technician,you should attain A+ certification. If you want to specialize in Microsoft product supportand development, pursue MCSE (Microsoft Certified Systems Engineer) certification. To spe-cialize in the configuration and management of Cisco Systems’ switches and routers, worktoward Cisco’s CCNA (Cisco Certified Network Associate) or go for their most difficultand prestigious distinction, CCIE (Cisco Certified Internetwork Engineer) certification. Toprove a mastery of many aspects of networking, you can choose to become Network+ certi-fied. Network+ (Net+) is a professional certification established by CompTIA that verifiesbroad, vendor-independent networking technology skills, such as an understanding of proto-cols, topologies, networking hardware, and network troubleshooting. Network+ may also bea stepping stone to more advanced certifications. The material in this book addresses theknowledge objectives you must understand to qualify for Network+ certification.

Certification is a popular career development tool for job seekers and a measure ofan employee’s qualifications for employers. Following are a list of benefits to becomingcertified:

• Better salary—Professionals with certification can usually ask for higher salaries thanthose who aren’t certified. Employers will also want to retain certified employees,especially if they helped pay for their training, and will offer incentives to keep certi-fied professionals at the company.

• Greater opportunities—Certification may qualify you for additional degrees or moreadvanced technical positions.

• Professional respect—After you have proven your skills with a product or system, yourcolleagues and clients will gain great respect for your ability to solve problems withthat system or product. They will therefore feel confident asking you for help.

• Access to better support—Many manufacturers reward certified professionals with lessexpensive, more detailed, and more direct access to their technical support.

One potential drawback of some certifications is the number of people attaining them—somany that certifications now have less value. Currently, hundreds of thousands of network-ing professionals have acquired the MCSE certification. When only tens of thousands ofpeople had MCSEs, employers were willing to pay substantially higher salaries to workerswith that certification than they are now. Other kinds of certifications, such as Cisco’s CCIEprogram, require candidates to pass lab exams. These kinds of certifications, because theyrequire rigorous proof of knowledge, are highly respected.

Finding a Job in NetworkingWith the proper credentials and demonstrated technical knowledge, you will qualify for amultitude of positions in networking. For this reason, you can and must be selective whensearching for a job. Following are some ways to research your possibilities:

18 Chapter 1

11• Search the Web—Because your job will deal directly with technology, it makes sense to

use technology to find it. Companies in the computer industry recruit intensively onthe Web, either through searchable job databases or through links on their companyWeb sites. Unlike firms in other industries, these companies typically do not mind (andmight prefer) receiving résumés and letters through e-mail. Most job database Websites do not charge for their services, but may require you to register with them. Somepopular general Web job databases include Yahoo! Hot Jobs at hotjobs.yahoo.comand, Monster at www.monster.com. IT-specific job sites include Dice at www.dice.com, Slashdot Jobs at jobs.slashdot.org, and computerjobs.com. A simple Web searchcould yield dozens more.

• Read the newspaper—A traditional place to look for jobs is the classified ad section ofyour local newspaper. Papers with large distributions often devote a section of theirclassified ads to careers in computing. Highlight the ads that sound interesting to you,even if you don’t have all of the qualifications cited by the employer. In some ads,employers will list every skill they could possibly want a new hire to have, but theydon’t truly expect one person to have all of them.

• Visit a career center—Regardless of whether you are a registered university or collegestudent, you can use career center services to find a list of job openings in your area.Companies that are hiring pay much attention to the collegiate career centers becauseof the number of job seekers served by these centers. Visit the college or universitycampus nearest you and search through its career center listings.

• Network—Find like-minded professionals with whom you can discuss job possibilities.You may meet these individuals through training classes, conferences, professionalorganizations, or career fairs. Let them know that you are looking for a job, and spec-ify exactly what kind of job you want. If they can’t suggest any leads for you, askthese people if they have other colleagues who might.

• Attend career fairs—Most metropolitan areas host career fairs for job seekers in theinformation technology field, and some large companies host their own job fairs. Evenif you aren’t sure you want to work for any of the companies represented at a job fair,attend the job fair to research the market. You can find out which skills are in highdemand in your area and which types of companies are hiring the most networkingprofessionals. You can also meet other people in your field who may offer valuableadvice based on their employment experience.

• Enlist a recruiter—Many recruiting agencies deal strictly with clients in the technicalfields. By signing up with such a recruiting agency, you may have access to job oppor-tunities that you didn’t know existed. You might also take advantage of a temporaryassignment, to see if the fit between you and an employer is mutually beneficial, beforeaccepting a permanent job with that employer.

Joining Professional AssociationsAt some point in your life, you have probably belonged to a club or organization. Youknow, therefore, that the benefits of joining can vary, depending on many factors. In thebest case, joining an organization can connect you with people who have similar interests,provide new opportunities for learning, allow you to access specialized information, andgive you more tangible assets such as free goods. Specifically, a networking professional


organization might offer its own publications, technical workshops and conferences, freesoftware, prerelease software, and access to expensive hardware labs.

You can choose from several prominent professional organizations in the field of networking.Because the field has grown so quickly and because so many areas in which to specialize exist,no single professional organization stands out as the most advantageous or highly respected.You will have to decide whether an organization is appropriate for you. Among other things,you will want to consider the organization’s number of members, membership benefits, mem-bership dues, technical emphasis, and whether it hosts a local chapter. Many organizationshost student chapters on university campuses. You may also want to find a professional asso-ciation that caters to your demographic group (such as Women in Technology International, ifyou are female). Table 1.1 lists some professional organizations and their Web sites.

Table 1-1 Networking organizations

Professional organization Web site

Association for Computing Machinery(ACM)

www.acm.org

Association for Information TechnologyProfessionals

www.aitp.org

IEEE Computer Society www.computer.org

Network Professional Association www.npanet.org

Women in Technology International(WITI)

www.witi.org

Chapter Summary■ A network is a group of computers and other devices (such as printers) that are con-

nected by some type of transmission media, such as copper or fiber-optic cable or theatmosphere, in the case of wireless transmission.

■ All networks offer advantages relative to using a stand-alone computer. Networksenable multiple users to share devices and data. Sharing resources saves time andmoney. Networks also allow you to manage, or administer, resources on multiplecomputers from a central location.

■ In a peer-to-peer network, every computer can communicate directly with every othercomputer. By default, no computer on a peer-to-peer network has more authority thananother. However, each computer can be configured to share only some of itsresources and keep other resources inaccessible.

■ Traditional peer-to-peer networks are usually simple and inexpensive to set up. How-ever, they are not necessarily flexible or secure.

■ Client/server networks rely on a centrally administered server (or servers) to manageshared resources for multiple clients. In this scheme, the server has greater authoritythan the clients, which are typically desktop or laptop workstations.

20 Chapter 1

11■ Client/server networks are more complex and expensive to install than peer-to-peer

networks. However, they are more easily managed, more scalable, and typically moresecure. They are by far the most popular type of network in use today.

■ Servers typically possess more processing power, hard disk space, and memory thanclient computers. To manage access to and use of shared resources, among other cen-tralized functions, a server requires a network operating system.

■ A LAN (local area network) is a network of computers and other devices that is con-fined to a relatively small space, such as one building or even one office.

■ LANs can be interconnected to form WANs (wide area networks), which traverse lon-ger distances and, therefore, require slightly different transmission methods and mediathan LANs. The Internet is the largest example of a WAN.

■ Client/server networks share some common elements, including clients, servers, work-stations, transmission media, connectivity devices, protocols, addressing, topology,NICs, data packets, network operating systems, hosts, backbones, segments, andnodes.

■ Although e-mail is the most visible network service, networks also provide services forprinting, file sharing, Internet access, remote access capabilities, communicating inmultiple forms, and network management.

■ File and print services provide the foundation for networking. They enable multipleusers to share data, applications, storage areas, and printers.

■ Networks use access services to allow remote users to connect to the network or net-work users to connect to machines outside the network.

■ Communications services provided by networks include e-mail, telephone, video, fax,messaging, and voice mail.

■ Mail services (running on mail servers) allow users on a network to exchange andstore e-mail. Most mail packages also provide filtering, routing, scheduling, notifica-tion, and connectivity with other mail systems.

■ Internet services such as World Wide Web servers and browsers, file transfer capabili-ties, addressing schemes, and security filters enable organizations to connect to and usethe global Internet.

■ Network management services centrally administer and simplify complicated manage-ment tasks on the network, such as asset management, security auditing, hardwareproblem diagnosis, backup and restore services, license tracking, load balancing, anddata traffic control.

■ To prepare yourself for a networking career, master a number of broad networkingskills, such as installing and configuring client and server hardware and software. Thenpick a few areas that interest you, such as network security or voice/data integration,and study those specialties.

■ Certification is the process of mastering material pertaining to a particular hardwaresystem, operating system, programming language, or other software program, thenproving your mastery by passing a series of exams. The benefits of certification caninclude a better salary, more job opportunities, greater professional respect, and betteraccess to technical support.

Chapter Summary 21

■ To excel in the field of networking, hone your soft skills, such as leadership abilities,written and oral communication, a professional attitude, dependability, and customerrelations.

■ Joining an association for networking professionals can connect you with like-minded people, give you access to workshops and technical publications, allow youto receive discounted or free software, and perhaps even help you find a job in thefield.

Key TermsA+ The professional certification established by CompTIA that verifies knowledge aboutPC operation, repair, and management.

access server See remote access server.

address A number that uniquely identifies each workstation and device on a network.Without unique addresses, computers on the network could not reliably communicate.

address management The process of centrally administering a finite number of networkaddresses for an entire LAN. Usually this task can be accomplished without touching theclient workstations.

addressing The scheme for assigning a unique identifying number to every workstationand device on the network. The type of addressing used on a network depends on itsprotocols and network operating system.

asset management The process of collecting and storing data on the number and typesof software and hardware assets in an organization’s network. The data collection isautomated by electronically examining each network client from a server.

backbone The part of a network to which segments and significant shared devices (such asrouters, switches, and servers) connect. A backbone is sometimes referred to as “a networkof networks,” because of its role in interconnecting smaller parts of a LAN or WAN.

backing up The process of copying critical data files to a secure storage area. Often,backups are performed according to a formulaic schedule.

CCIE (Cisco Certified Internetwork Expert) An elite certification that recognizes expert-levelinstallation, configuration, management, and troubleshooting skills on networks that use arange of Cisco Systems’ devices.

CCNA (Cisco Certified Network Associate) A professional certification that attests to one’sskills in installing, configuring, maintaining, and troubleshooting medium-sized networksthat use Cisco Systems’ switches and routers.

certification The process of mastering material pertaining to a particular hardware system,operating system, programming language, or other software program, then proving yourmastery by passing a series of exams.

Cisco Certified Internetwork Expert See CCIE.

Cisco Certified Network Associate See CCNA.

client A computer on the network that requests resources or services from anothercomputer on a network. In some cases, a client could also act as a server. The term client

22 Chapter 1

11may also refer to the user of a client workstation or a client software application installedon the workstation.

client/server architecture A network design in which clients (typically desktop or laptopcomputers) use a centrally administered server to share data, data storage space, and devices.

client/server network A network that uses centrally administered computers, known asservers, to enable resource sharing for and to facilitate communication between the othercomputers on the network.

CompTIA (Computing Technology Industry Association) An association of computerresellers, manufacturers, and training companies that sets industry-wide standards for computerprofessionals. CompTIA established and sponsors the A+ and Network+ (Net+) certifications.

Computing Technology Industry Association See CompTIA.

connectivity device One of several types of specialized devices that allows two or morenetworks or multiple parts of one network to connect and exchange data.

convergence The use of data networks to carry voice (or telephone), video, and othercommunications services in addition to data.

data packet A discrete unit of information sent from one node on a network to another.

file server A specialized server that enables clients to share applications and data acrossthe network.

file services The functions of a file server that allow users to share data files, applications,and storage areas.

host A computer that enables resource sharing by other computers on the same network.

Internet A complex WAN that connects LANs and clients around the globe.

Internet services The services that enable a network to communicate with the Internet,including World Wide Web servers and browsers, file transfer capabilities, Internetaddressing schemes, security filters, and a means for directly logging on to other computers.

LAN (local area network) A network of computers and other devices that is confined to arelatively small space, such as one building or even one office.

license tracking The process of determining the number of copies of a single applicationthat are currently in use on the network and whether the number in use exceeds theauthorized number of licenses.

load balancing The process of distributing data transfer activity evenly across a network sothat no single device is overwhelmed.

local area network See LAN.

mail server A server that manages the storage and transfer of e-mail messages.

mail services The network services that manage the storage and transfer of e-mail betweenusers on a network. In addition to sending, receiving, and storing mail, mail services caninclude filtering, routing, notification, scheduling, and data exchange with other mail servers.

MAN (metropolitan area network) A network that is larger than a LAN, typicallyconnecting clients and servers from multiple buildings, but within a limited geographic area.For example, a MAN could connect multiple city government buildings around a city’scenter.

Key Terms 23

management services The network services that centrally administer and simplifycomplicated management tasks on the network. Examples of management services includelicense tracking, security auditing, asset management, address management, softwaredistribution, traffic monitoring, load balancing, and hardware diagnosis.

MCSE (Microsoft Certified Systems Engineer) A professional certification established byMicrosoft that demonstrates in-depth knowledge about Microsoft products.

metropolitan area network See MAN.

Microsoft Certified Systems Engineer See MCSE.

motherboard The main circuit board that controls a computer.

network A group of computers and other devices (such as printers) that are connected byand can exchange data via some type of transmission media, such as a cable, a wire, or theatmosphere.

network adapter See NIC.

Network+ (Net+) The professional certification established by CompTIA that verifiesbroad, vendor-independent networking technology skills, such as an understanding ofprotocols, topologies, networking hardware, and network troubleshooting.

network interface card See NIC.

network operating system See NOS.

network services The functions provided by a network.

NIC (network interface card) The device that enables a workstation to connect to thenetwork and communicate with other computers. NICs are manufactured by severaldifferent companies and come with a variety of specifications that are tailored to theworkstation’s and the network’s requirements. NICs are also called network adapters.

node A computer or other device connected to a network, which has a unique address andis capable of sending or receiving data.

NOS (network operating system) The software that runs on a server and enables the serverto manage data, users, groups, security, applications, and other networking functions. Themost popular network operating systems are Microsoft Windows NT, Windows 2000Server, and Windows Server 2003, UNIX, Linux, and Novell NetWare.

P2P network See peer-to-peer network.

peer-to-peer network A network in which every computer can communicate directlywith every other computer. By default, no computer on a peer-to-peer network hasmore authority than another. However, each computer can be configured to share onlysome of its resources and keep other resources inaccessible to other nodes on thenetwork.

print services The network service that allows printers to be shared by several users on anetwork.

protocol A standard method or format for communication between network devices.Protocols ensure that data are transferred whole, in sequence, and without error from onenode on the network to another.

24 Chapter 1

11remote access server A server that runs communications services that enable remote usersto log on to a network. Also known as an access server.

remote user A person working on a computer on a different network or in a differentgeographical location from the LAN’s server.

resources The devices, data, and data storage space provided by a computer, whetherstand-alone or shared.

restore The process of retrieving files from a backup. It is necessary to restore files if theoriginal files are lost or deleted.

scalable The property of a network that allows you to add nodes or increase its size easily.

security auditing The process of evaluating security measures currently in place on anetwork and notifying the network administrator if a security breach occurs.

segment A part of a network. Usually, a segment is composed of a group of nodes thatshare the same communications channel for all their traffic.

server A computer on the network that manages shared resources. Servers usually havemore processing power, memory, and hard disk space than clients. They run networkoperating software that can manage not only data, but also users, groups, security, andapplications on the network.

sneakernet A way of exchanging data between computers that are not connected on anetwork. Sneakernet requires that data be copied from a computer to a removable storagedevice such as a floppy disk, carried (presumably by someone wearing sneakers) to anothercomputer, then copied from the storage device onto the second computer.

soft skills The skills such as customer relations, leadership ability, anddependability, which are not easily measured, but are nevertheless important in anetworking career.

software distribution The process of automatically transferring a data file or installing asoftware application from the server to a client on the network.

spam An unsolicited, unwanted e-mail.

stand-alone computer A computer that uses applications and data only from its local disksand that is not connected to a network.

topology The physical layout of computers on a network.

traffic The data transmission and processing activity taking place on a computer networkat any given time.

traffic monitoring The process of determining how much data transfer activity is takingplace on a network or network segment and notifying administrators when a segmentbecomes overloaded.

transmission media The means through which data are transmitted and received.Transmission media may be physical, such as wire or cable, or atmospheric (wireless), suchas radio waves.

unified communications The centralized management of multiple types of network-basedcommunications, such as voice, video, fax, and messaging services.

Key Terms 25

user A person who uses a computer.

WAN (wide area network) A network that spans a long distance and connects two or moreLANs.

Web server A computer that manages Web site services, such as supplying a Web page tomultiple users on demand.

wide area network See WAN.

workstation A computer that runs a desktop operating system and connects to a network.

Review Questions1. Which of the following distinguishes peer-to-peer networks from client/server

networks?

a. In peer-to-peer networks, only one computer can send and receive transmissions onthe network.

b. In peer-to-peer networks, only one type of protocol suite can be used to send andreceive data.

c. In peer-to-peer networks, a central computer manages all file and print sharing.

d. In peer-to-peer networks, no single computer has more authority than another, bydefault.

2. Which of the following is an advantage of using a peer-to-peer network over using aclient/server network?

a. A peer-to-peer network allows for more nodes.

b. A peer-to-peer network provides greater security.

c. A peer-to-peer network is easier to set up.

d. A peer-to-peer network allows for easier expansion.

3. Which of the following is an advantage of using a client/server network over using apeer-to-peer network?

a. A client/server network is simpler to set up.

b. A client/server network allows for easier expansion.

c. A client/server network does not require a network operating system.

d. A client/server network is less expensive to set up.

4. The first services widely used by networks were:

a. Mail services

b. Communications services

c. Network management services

d. File and print services

26 Chapter 1

115. Suppose you wanted to share documents among several computers in your household in

a peer-to-peer fashion. You could do that by properly configuring which of the follow-ing types of software?

a. Word-processing software

b. Desktop operating system software

c. Mail client software

d. Remote authentication software

6. What is the primary function of a file server on a network?

a. It routes traffic between two or more LANs.

b. It monitors how many users are logged on to a WAN.

c. It prevents unauthorized remote users from connecting to a LAN.

d. It manages access and use of shared applications and data.

7. On most LANs, a computer acting as a server differs from a computer acting as a clientin which of the following ways? (Choose two answers.)

a. The server would have a faster connection to the network than the client.

b. The server would run different network protocols than the client.

c. The server would support connections to more media types than the client.

d. The server would run a different operating system than the client.

e. The server would possess greater processing power than the client.

8. In which of the following environments would a MAN be most appropriate?

a. A corporate headquarters connecting its five buildings across a small campus

b. A global hotel chain connecting its reservation desks to a central call center

c. A home office connecting its personal computers between the den, living room, andbedroom

d. A local newspaper connecting to a global news agency’s Web site

9. Which of the following describes the combination of voice (such as telephone), video,and data signals sent over the same network?

a. Switching

b. Remote access

c. Convergence

d. Network management

10. What is the term used to describe a discrete unit of data that is sent from one node toanother over the network?

a. Capsule

b. Node

c. Packet

d. Parcel

Review Questions 27

11. How can a server tell the difference between many clients on a network?

a. Each has a different electromagnetic characteristic to its signal, similar to differencesin human voices.

b. Each regularly transmits a signal that indicates its network location and uniqueclient characteristics.

c. Each is identified by a unique network address.

d. Each uses uniquely modified versions of the same network protocol.

12. What device connects a client computer to a network’s medium, such as a wire?

a. Network interface card

b. Network terminator

c. Network junction clip

d. Network line extender

13. Which of the following is one function of a network protocol?

a. To ensure that connectivity devices are configured properly

b. To establish rules for routing mail messages in an organization

c. To ensure that data arrives at its destination in the proper sequence

d. To prevent unauthorized users from logging on to a file server

14. The physical layout of nodes on a network is known as the network’s:

a. Schematic

b. Topology

c. Formation

d. Grid

15. Which of the following is an example of a mail service?

a. Exchanging messages between mail servers on different networks

b. Ensuring that users are not running more copies of an e-mail client than have beenpurchased

c. Preventing unauthorized users from gaining access to the network and, in particu-lar, to its mail server

d. Enabling users to print messages from their e-mail client software

16. Which of the following network topologies is most common on today’s networks?

a. Fan

b. Star

c. Ring

d. Bus

28 Chapter 1

1117. Which of the following is an example of a network management service?

a. Establishing permissions for users and groups of users to access certain applicationson the server

b. Alerting the network administrator when a critical connectivity device fails

c. Managing the queue of print jobs during periods of heavy network traffic

d. Supplying users with file transfer capabilities over the Internet

18. Security is a concern when using remote access servers on a network because:

a. Access servers enable computers to dial in to a network and obtain access to itsresources, thereby exposing the network to the outside world.

b. Access servers have poor password enforcement capabilities and rely on users tochoose good passwords.

c. Access servers cannot accept encoded data transfers, requiring users to transmitplain text to and from the network.

d. Access servers are difficult to understand and support, and so many networks areusing them incorrectly and perhaps insecurely.

19. Distributing data transfer activity equally over several devices or components belongs towhich category of network management services?

a. Load balancing

b. Asset management

c. Traffic monitoring

d. File and print services

20. What organization sponsors the CCNA and CCIE certifications?

a. IEEE

b. CompTIA

c. Cisco

d. WITI

Hands-On Projects

Project 1-1During your career in networking, you will frequently need to interpret net-work drawings, if not create them yourself. Although seasoned networkingprofessionals use software to help them depict a network, many designs start

with a simple sketch. To familiarize yourself with network components and layout, in this projectyou will draw some simple network diagrams. This project requires only pencil and paper. If youneed help remembering what each network topology looks like, refer to Figure 1-7.

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Hands-On Projects 29

1. On your sheet of paper, draw a basic bus topology with four computers attached to thebackbone, or bus. Label the computers A, B, C, and D.

2. Now imagine that the user at computer A needs to open a file on computer D, in a peer-to-peer fashion. What path do you think the data will follow from A to D and thenfrom D to A? Add this path, as a dotted line, to your network diagram.

3. On the opposite side of your paper, using no more than half of a page, draw a startopology with four computers attached to a central connectivity device. Label the work-stations E, F, G, and H.

4. Imagine that the user at computer E wants to open a file that is on computer H’s harddisk, in a peer-to-peer fashion. With a dotted line, draw the path you think data wouldtake between these two computers.

5. Now add a printer and a server to your star-topology network drawing. With the addi-tion of a server, you have changed the network from a peer-to-peer network to a client/server network. The printer has become a resource that all the workstation users canshare.

6. Suppose the new server is configured to provide all necessary services to the entire star-topology network, including print and file services. Now if computer G sends a docu-ment to the printer, what path do you think the document’s data will take to theprinter? Draw this path as a dotted line on your network.

7. Often, modern networks are not simple star, bus, or ring topologies. Sometimestwo or more star-shaped networks are connected via a bus to create a star-bustopology. On the same sheet of paper, draw a second star topology network thatconsists of three workstations, labeled I, J, and K, and linked to a central connec-tivity device.

8. Now draw a line between the two connectivity devices to indicate a bus-style connectionbetween the star-based networks. You have now designed a hybrid star-bus topologynetwork.

9. Suppose that workstation J wants to print to the printer you added in Step 5. Using adotted line, draw the path you think workstation J’s document will take to the printer.Remember that the server still controls all print functions for that network.

10. Of the three different kinds of networks you worked on in this project, which one doyou think would allow for the easiest expansion?

11. Considering the amount of hardware and cabling involved, which of the three networkswould be least expensive to implement?

Project 1-2There is no substitute for hands-on practice when it comes to configuring net-work clients and servers. Although you have only just learned about the basicelements common to all client/server networks, you can see evidence of these

elements on most any desktop computer. In this project, you will navigate through some simple net-working features on a client workstation. Later projects in this book will require you to be very

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11familiar with the location and operation of the dialog boxes pertaining to networking properties. Forthis project, you will need a workstation running the Microsoft Windows XP operating system. Itdoes not necessarily have to be connected to a network. However, it should contain at least onefunctional network adapter.

Note that this project and other projects in this book assume you arerunning Windows XP in the Classic View, which is the default afterinstallation. Projects in this book also assume that you have installedService Pack 2 on your Windows XP computer.

1. Depending on the operating system they use, clients differ in how their network connec-tions are configured. To view a workstation’s network connections in Windows XP,click Start on the taskbar, then click My Network Places. The My Network Places win-dow appears.

2. This window contains icons that represent connections to shared resources on yourLAN. If your computer is not connected to a LAN, you might still see icons representingresources on your hard disk that are available for sharing over a network or with otherusers of your PC.

3. On the left side of the My Network Places window, under the heading Network Tasks,click View network connections. The Network Connections window opens, as shown inFigure 1-9.

4. If your workstation is connected to a network, an icon that depicts two computers nextto each other, titled Local Area Connection, appears. If your workstation is not con-nected to a network, but contains a functional NIC, the same icon appears with a redX on one of the lines. In Figure 1-9, for example, the Wireless Network Connection is

Figure 1-9 The Network Connections window

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not active. Choosing the View network connections option would be helpful, for exam-ple, if you need to determine whether your connection to the network is active.

5. Click the Back button to return to the My Network Places window.

6. Click the Shared Documents folder under the Other Places heading on the middle of theleft side of the My Network Places window. The Shared Documents window opens. Theright side of this window contains icons representing folders and files currently beingshared or made available to other network users. Recall that sharing folders is a simpleway of exchanging data over a peer-to-peer network.

7. Typically, the folders in the Shared Documents window will include at least the follow-ing: Shared Music, Shared Pictures, and Shared Video. Right-click the Shared Musicfolder and click Sharing and Security on the menu that appears. The Shared MusicProperties dialog box opens.

8. Click the Sharing tab, if necessary, to view the options under the Sharing tab in theShared Music Properties dialog box, as shown in Figure 1-10.

Figure 1-10 Sharing tab in the Shared Music Properties dialog box

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119. Read the text under the Network sharing and security heading. Click the Share this

folder on the network setting. Notice that a share name appears, and by default, it iscalled “Shared Music.” (If this is the first time file sharing has been selected on thisworkstation, you will need to first bypass the Network Setup Wizard option. To do so,click If you understand the security risks but want to share files without running thewizard click here.) The share name is how the shared folder is identified to other userson the network. However, you could change the text of the default share name to what-ever you want.

10. Click Cancel to close the Shared Music Properties dialog box without saving yourchanges. You have now learned a simple way to share your computer’s files with otherusers on the network. Notice that this method of file sharing does not require a networkoperating system.

11. Close the Shared Documents window.

Project 1-3In Project 1-2 you learned where network connections are shown and how to setup file sharing on a computer running the Windows XP operating system. In thisexercise, you learn the same on aWindows Vista computer. For this project, you

need a desktop or laptop computer running the Windows Vista operating system. It doesn’t necessarilyhave to be connected to a network. However, it should contain at least one functional network adapter.In addition, you should be logged onto the workstation as a user with administrator-equivalentprivileges.

1. To view your workstation’s network connections in Windows Vista, click the Start but-ton on the taskbar, then select Control Panel. The Control Panel window appears.

2. Under the Network and Internet heading, click View network status and tasks. The Net-work and Sharing Center window appears, displaying your network connections, asshown in Figure 1-11.

3. If your workstation is connected to a network, this will be represented by a line betweenan icon that represents your computer and an icon that represents your LAN (local areanetwork) or network connection device (for example, a gateway). Furthermore, if yourLAN is connected to the Internet, the window will also reveal that, as seen in Figure 1-11.

4. If your workstation is connected to a network, click View status (to the far right in theConnection line) to learn more about this connection. The Local Area Connection Sta-tus window appears (assuming the connection you chose was a LAN connection), asshown in Figure 1-12. Note that from this window you can find out whether your con-nection supports IPv4 or IPv6 connectivity (both protocols are discussed in detail inChapter 4), the duration, and the speed of your connection, among other things.

5. Click Close to close the Local Area Connection Status window and return to the Net-work and Sharing Center window.

6. Notice the options below the Sharing and Discovery heading in this window. These optionsallow you to share files and locally attached printers in various ways. To get a sense of howthis is accomplished, click the down arrow to the right of the Public folder sharing option.A list of choices related to sharing files in the computer’s public folder appear.

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7. Click Turn on sharing so anyone with network access can open files, then click the Applybutton. This will allow any user who has logged on to the network to read the files in yourcomputer’s public folder, but not to change or delete those files. (A public folder is simply adirectory on your hard disk that is specially designated for storing publicly shared files.)

8. A User Account Control window appears, requiring you to confirm your choice. ClickContinue to do so. (If you are not logged on as an administrator, you might also beprompted for an administrator password.) If you receive a message asking whether youwant to turn on network discovery and file sharing for all public networks, click “No,make the network that I am connected to a private network.”

9. After returning to the Network and Sharing Center window, notice that the File sharingand Password protected sharing options have also been turned on, based on your deci-sion to allow public folder sharing.

10. To remove public folder sharing privileges, click the down arrow next to the Publicfolder sharing option, click Turn off sharing (people logged on to this computer canstill access this folder), then click Apply to save your changes.

11. Click Continue to confirm your choice. (If you are not logged on as an administrator,you might be prompted for an administrator password.)

12. Click the down arrow on the right side of the File sharing line.

13. From the options that appear, click Turn off file sharing, then click Apply.

Figure 1-11 Network and Sharing Center

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11

14. Click Continue to confirm your choice. (If you are not logged on as an administrator,you might be prompted for an administrator password.)

15. Close the Network and Sharing Center window.

Project 1-4Even before you are ready to look for a job in networking, you should be famil-iar with the kinds of employers who are looking for IT professionals and theskills that they desire. The more research you do, the better prepared you will be

when you begin job hunting in earnest. This project will familiarize you with searching job databases onthe Web. To complete this project, you need a computer with a Web browser and access to the Internet.

Steps in this project matched the Web sites mentioned at the time this book was published. If younotice discrepancies, look for similar links and follow the same general steps.

1. Access the Internet and point your Web browser to www.monster.com.

2. In the Keywords text box next to the Job Search prompt, type network technician. Fornow, accept the default settings for the other options, such as Occupations and

Figure 1-12 Local Area Connection Status window

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Locations, and click Search to search Monster’s database for jobs that contain thewords network technician. How many jobs were returned by the search?

3. Next, examine the different skills required for each position. Click the first 15 uniquejob postings, one after the other, to display the job descriptions. For those that includesufficient details, make a check mark next to the following proficiencies to indicatehow many of the jobs require or recommend each proficiency or certification level:

• UNIX or Linux

• Microsoft operating systems (for example, Windows XP, Windows Vista, WindowsServer 2003, or Server 2008)

• Firewalls or network security

• Cisco hardware

• Converged services (for example, VoIP, which stands for voice over IP, or IP telephony)

• Remote access services

• Database software (for example, SQL)

• Backup and recovery (or disaster recovery)

• Network management

• Project management

• Network+ certification

• Cisco certification (such as CCNA or CCIE)

• A+ certification

• MCSE certification

4. For each proficiency, calculate the percentage of the jobs you surveyed that require it.

5. Return to the Monster home page. Once again, type network technician in the Key-words text box, then in the Locations text box, type in the name of your city and state.If you don’t live in a large city, click the down arrow in the Radius drop-down list boxand choose a radius of 100 mile.

6. Click the Search button. How many jobs did the search return? Which areas have themost job openings?

7. Click the Back button to return to the Monster home page again. In the Keywords textbox, type network manager. Remove the geographical data you entered below the Loca-tions and Radius headings in the previous step. Then, under the Occupations heading,click the down arrow to view a list of business sectors, then click IT/Software Develop-ment. From the list that appears beneath that heading, choose at least four areas withinthe IT field. Finally, click the Search button to start the search.

8. How many results did this search return?

9. Examine the first 15 jobs. Next to the following soft skills, write down the number ofthese jobs that require each skill:

• Leadership

• Strong oral/written communication

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11• Customer relations

• Teamwork

• Supervision

• Motivation (of yourself and others)

10. Continue to search the Monster database, choosing keywords or categories for specialtyareas of networking that appeal to you. Some examples might be network security,voice/data integration, or router configuration.

11. As you read the job descriptions, jot down terms and skills that are new to you, thenlook up their definitions in the glossary of this text.

12. When you have finished, close your Web browser.

Case Projects

Case Project 1-1You have been asked by Thrift Towne, a local charity retail organization, toinstall a network in its downtown office. It currently has four PCs runningWindows XP Professional, with the following specifications:

• Pentium III, 500 MHz processor, 256 MB memory, 10 GB hard drive

• Pentium 4, 1 GHz processor, 512 MB memory, 40 GB hard drive

• Pentium 4, 3 GHz processor, 1 GB memory, 120 GB hard drive

• Pentium 4, 3 GHz processor, 2 GB memory, 250 GB hard drive

Thrift Towne’s owners are not very concerned about security, because the net-work will share only staff schedules and inventory information (customersremain anonymous and are not tracked) between its own PCs. Thrift Towneuses mostly volunteers to run its stores, and the volunteers are not technicalexperts, so they are hoping for a solution that doesn’t require any complexmaintenance. In addition, Thrift Towne doesn’t have much money to spendon this project. In short, the owners have asked for a simple, inexpensive solu-tion. What type of network would you recommend and why? What kind ofadditional equipment would Thrift Towne have to purchase to make yoursolution work? What role (or roles) would you assign to each of the fourworkstations and any other equipment you recommend? What type ofupgrades, if any, might the workstations require to make your solution work?

Case Project 1-2Your work at Thrift Towne was so successful that you are asked to providenetworking advice to a chain of ice cream stores called Scoops. Scoops alreadyhas a server-based network. The server that holds the company’s inventory,ordering, sales, time tracking, and employee information and provides anInternet connection is located at their store across the street from ThriftTowne. Three other Scoops stores in town connect to the central server

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through high-speed Internet connections. Scoops is having problems withheavy traffic and slow server response at 8:00 a.m. and 3:00 p.m. each day.They don’t exactly know where the traffic originates or what type of traffic itis. They also don’t know whether the two heavy traffic times every day war-rant a change in their connection methods. Using what kind of network ser-vices will help them assess their traffic situation and provide answers aboutpossible network expansion? What types of things can they find out? Whatother kinds of services might they also use, given their network configuration?

Case Project 1-3The client/server network at Scoops currently depends on one server machinerunning Windows Server 2003 as its NOS. However, the system was installedfive years ago, and the chain is growing. The company’s general manager hasheard a lot of good things about Linux operating systems—in particular, atype of Linux called Ubuntu. He asks you to find out how these two NOSsdiffer in their file sharing, remote access, and mail service capabilities. Also,he wonders how the two compare in their ease of use, reliability, and support.He remarks that he doesn’t want to spend a lot of time looking after theserver, and reminds you that he is not a technical expert. After some research,what can you tell him about the similarities and differences between these twoNOSs? Do you advise the Scoops chain to change its server’s NOS to Linux?Why or why not?

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