Home Networking Bible 2nd phần 2 pptx

47 Chapter 3 ✦ Understanding Workgroup Networking On the other hand, when you back up your files to your spouse’s computer, you probably will not need to access the files at all. Generally, you need to access a backup only if something happens to your original files — corruption, disk failure, and the like. The process of backing up, however, takes longer than just saving one file to another computer. Also, because you should back up your files frequently, you will need to access your spouse’s computer every time you back up. For more information about performing backups, see Chapter 21. You must be sure to arrange for backups in an office setting. You may want to include two sets of backups, using different computers or even mass storage devices, such as a tape drive. You have to weigh the inconvenience and expense of backing up against the inconve- nience and expense of re-creating your accounting, payroll, and customer information. Disk space You need to consider each computer’s hard disk space before deciding which computer to use for file storage and backups. A computer with only 2 to 5GB of disk space cannot reason- ably store many graphics files or music files, for example. However, a 2 to 5GB drive could comfortably store word processing and spreadsheet documents, in addition to several appli- cations. Most new computers come with much larger hard drives now. It’s not unusual to see drives that offer 40, 60, 80, or more gigabytes of space. Depending on your computer’s hard disk space, you might want to divide the file storage duties. You could back up all files to one computer, or back up your files to your spouse’s machine, your spouse’s files to your son’s machine, and your son’s files to your machine. Plan ahead, depending on the hard disk sizes of your computers. Computer power and memory Consider, too, the power and memory of each computer on the network. A very slow machine, such as a 300 MHz, might not be the appropriate choice for containing files that need to be accessed often. Such a computer slows down the rest of the network when accessed frequently. Similarly, computers with less memory react more slowly than those with more memory. Reserve the Windows 98 computer with only 64MB of RAM and a Pentium II processor for network jobs that aren’t processor- and memory-intensive. Use the Windows XP Professional computer with 256MB of RAM and a Pentium IV processor for backing up files quickly and effectively. Dividing resources The members of a workgroup network act as both the client and the server. As a server, each computer shares its files and resources; as the client, each computer partakes of the others’ resources. You must consider the resources you’ll be using on the network. You can assign resources — such as printers, scanners, storage devices, and so on — to cer- tain computers in your network so that everyone has access but no one computer is bur- dened by the load. Figure 3-6 shows one solution to resource placement. The laser printer is located on the first floor of the house because there are two computers downstairs and only one upstairs. The scanner, on the other hand, is upstairs because the teenager uses it the most and that com- puter has the appropriate hardware to run the scanner. The other two computers are on the network, however, so they can access scanned images anytime from the teenager’s computer. Small Business Tip 48 Part I ✦ Making Basic Network Choices Figure 3-6: Place resources where they are most convenient. Typically, all computers on the network share all their resources with the others. It is possible, however, to limit which folders, files, and such can be shared by whom. For example, Windows computers use a sharing system to limit the access others can have to the machine. If you want to share files, you can make them available to everyone, or you can make them available only to those who have the appropriate password. Alternatively, you can choose not to share a resource at all. See Chapter 12 for more information. For each resource you add to the network, you must determine which computer best suits that resource’s requirements. Consider the requirements for scanners, printers, CD-ROM drives, modems, and others. Remember, too, that when you share a resource, the computer attached to that resource will take a performance hit whenever the resource is being used. If your business uses several different printers, scanners, or other special devices that you plan to share over the network, consider using a client/server network for more efficient del- egation of services. Small Business Tip Note 49 Chapter 3 ✦ Understanding Workgroup Networking When you install a scanner on a computer, you also need to install an adapter card and scan- ner software. That means the computer on which you install the hardware must have a free slot for the adapter card and room enough for the scanning program. Scanned images create large files, so you’ll need plenty of storage space. Additionally, scanning requires substantial memory and processor speed. The computer to which you install a modem and with which you connect to the Internet also must have considerable memory and processor speed for quick and easy access. The soft- ware for sharing an Internet account has special requirements; alternatively, you can use a piece of hardware (called a router) to share Internet connections. See Chapter 12 for more information. Temporary Internet files and cookies take up a lot of disk space as well. Cookies are identi- fiers saved on your hard disk during your visits to various Web pages. Software on the Web sends the cookie to collect information — such as your name, e-mail address, site password, and so on — and then logs that information on your hard disk. The next time you visit that particular site, software from the site recalls the cookie so that it knows who you are. Most cookies are harmless. Figure 3-7 shows the C:\Windows\Cookies folder with several cookies listed in the folder. Note that these are very small text files. You can delete them periodically to make more room on your computer; when you delete a cookie for an Internet site you visit often, however, you also may be deleting a saved password and username that makes it easier for you to get onto that site. Figure 3-7: Delete cookies if you want to make more disk space available. 50 Part I ✦ Making Basic Network Choices If you use a Web connection on your small-business network, you should certainly employ some sort of security. It’s common for crackers to break into local networks from the Internet and pilfer business records, confidential files, payroll information, and more. The cracker could be your competition, a disgruntled employee, or even a kid experimenting with appli- cations built for cracking systems. Consider using software such as a firewall or a proxy server. For more information, see Chapter 16. You may prefer to back up files or store files on a CD drive, Zip drive, or other mass storage device. When deciding whether to attach the storage device to a computer, check compatibil- ity as well as requirements. Tape drives are often difficult to install on some computers, for example. CD drives are easy to use, inexpensive, and popular for storing and backing up files. Understanding the Limits of Workgroup Networking Workgroup networks offer many advantages for the home network. You can share resources and files with other users, read each other’s schedules, learn about e-mail, and share an Internet access account, for example. You also can experience some real problems with a workgroup network. As mentioned earlier in the chapter, workgroup networking can place a strain on individual computers and on resources, especially if the requests for use of the resource or network traffic is high. Also, workgroup networking offers little security for your files and data, and it limits the number of people you can attach to the network. Understanding the limits of a workgroup network will help you determine some solutions to the problems. Considering performance Your network performance depends on many issues. You should make sure that you have suf- ficient computer power, and you need to consider the networking equipment you’ll use. The most positive aspect of performance is that you can always upgrade your equipment. In home networking, you can begin building your network with even the most minimal com- puter and networking equipment. After you use the network for a while, you can decide if the performance is adequate for your needs. For this plan to work, however, you need to be sure your initial purchases are upgradable. For example, if you purchase a computer, check to see if you can add additional hard disks, if you have plenty of slots for adapter cards, and if the memory is easy to find and upgradable. With your network hardware purchases, you also should plan ahead. When you buy network cards, buy cards that fit several different cabling types and speeds, if possible. When you buy cabling, don’t limit your upgrade choices. For more information about network cards, see Chapter 9. For more information about cabling, see Chapters 6, 7, and 8. Cross- Reference Small Business Tip 51 Chapter 3 ✦ Understanding Workgroup Networking Thinking about security issues You probably won’t need to worry too much about security issues in your home network. You most likely trust your spouse and your children with any information on the network. There are, however, a few issues to consider. ✦ First, accidents happen. Someone could access your hard disk accidentally and delete a few files, a folder or two, or your entire hard disk’s contents. This kind of potential problem is a security issue. ✦ Second, a child could always bring home a friend who fancies him- or herself a hacker. It’s not too unlikely that such a kid could access and then alter, delete, or just read your private files. ✦ Third, if you have an Internet connection, the possibility always exists that someone could crack your system and compromise your data. Most operating systems provide some safety measures that can protect your files from access by others on the network. You can choose which files to share and which remain pri- vate. Also, applications are available that enable you to control other computers on the net- work so that files, settings, and configurations are not accessible by anyone without a password. Finally, you can add software to your network to help protect it from intruders via the Internet. For more information about limiting access to your files and your computer, see Chapter 12. For more information about Internet security, see Chapter 16. As you plan your network, remember the possible problems and solutions and build them into your plan. Limiting the number of users As you know by now, a workgroup network limits the number of users you can add to your network. Ten users are the most you can connect before you start to see a major deficit in performance. Even if you have fewer than ten users, you can experience performance prob- lems. Three or four users who use network resources heavily can slow down performance and hinder everyone’s computer and network operation. If you have any idea at all that you’ll be adding more users or heavy-usage users to your net- work, consider using high-performance networking equipment, such as Ethernet or Fast Ethernet. You also should consider using a client/server network. Ethernet and Fast Ethernet are networking technologies that provide speed and superior per- formance. For more information, see Chapter 6. A client/server network may better serve your needs by using a dedicated server and specialized software. See Chapter 4 for more information. Troubleshooting Workgroup Networks Troubleshooting a workgroup network is fairly easy. First, a workgroup network has only a few users and computers to check when something goes wrong. Second, after the initial setup, only a few things can go wrong to make the network stop working. As far as adminis- tering a workgroup network is concerned, your job will be easy. Cross- Reference 52 Part I ✦ Making Basic Network Choices Solving workgroup networking problems depends on the hardware you use to build your net- work. Unless someone changed the configurations, the problem isn’t likely to be in the net- working software. When a connection or access problem occurs, you should check all connections to the network: A cable or network card could be the problem. Replacing these networking items is quick and easy. Each chapter of this book includes some troubleshooting tips. Additionally, check Appen- dix A for information on specific problems. Summary In this chapter, you learned about workgroup networking. Specifically, you learned about the following: ✦ Understanding workgroup requirements ✦ Dividing up computer duties and resources ✦ Understanding the limits of workgroup networking In the next chapter, you learn about client/server networking. ✦✦✦ Understanding Client/Server Networking A client/server network might work for you if you have special cir- cumstances that require a server, such as a database program that must run on a server. You may want to work with a server for the knowledge and experience of setting up and managing a more compli- cated network. Although the client/server type of network is more expensive and takes more administrative time than workgroup, there is a definite place for its use in networking today. Understanding Client/ Server Requirements A client/server network consists of two or more client, or user, com- puters and at least one server computer. In a true client/server situa- tion, the client computers do not use each other’s resources, only those of the server. The server computer controls all files, folders, printers, and other resources on the network. A small network might use one server for 2 or 100 clients. As net- works expand and the need for services increases, you can add multiple servers to a network. Very large networks might use 10 or 20 servers, for example, that serve hundreds or thousands of clients. Client/server networking lightens the load for the client PCs. Clients can use the server to store files and to perform some processes, such as monitoring print jobs and running certain applications. The server’s load, on the other hand, increases, especially as more and more clients request services. Figure 4-1 illustrates a simple client/server network. The server is a powerful computer that authenticates users and supplies files, fold- ers, and resources to the users. The server also controls the network printer. Client computers must send a request to print, access a file, and so on, to the server first. Note that the hub is the central connec- tion for all cables. Note 4 4 CHAPTER ✦✦✦✦ In This Chapter Understanding client/server requirements Considering network operating systems Looking at available network operating systems Looking at client operating systems ✦✦✦✦ 54 Part I ✦ Making Basic Network Choices Figure 4-1: A simple client/server network using traditional cabling methods Servers generally use faster processors and have more memory (RAM) and disk space to per- form the management of the network. Servers perform multiple duties, including the following: ✦ Authenticating users ✦ Allowing access to resources — files, folders, printers, and so on ✦ Providing Web access ✦ Tracking resource usage ✦ Logging security breaches ✦ Distributing e-mail ✦ Providing application access and data The client/server network has many advantages and disadvantages. You can read more about these in Chapter 2. Note Hub Server Clients Printer 55 Chapter 4 ✦ Understanding Client/Server Networking Considering network requirements The requirements for the clients on a client/server network are similar to those of a work- group network. Usually, a client/server network uses two or more client computers attached to a server computer. Although having only one client and one server in a client/server net- work is possible, you may not need a server in this situation. See Chapter 2 for more informa- tion on deciding whether to use a workgroup network or a client/server network. For each computer on the network, you need a network adapter card. Compatible cabling is also necessary, as well as any other networking hardware, such as a hub, switch, or phone jacks. See Chapters 6, 7, and 8 for more information. You can add printers and other resources to your network as well. When you add resources, you choose whether to attach them to a local computer or to the server computer. For exam- ple, you might have a laser printer you attach to the server and let everyone share. On the other hand, you also might have a color inkjet or an old dot-matrix printer that you attach to just one machine for use by that one person. Figure 4-2 illustrates a small client/server network in which the users share the laser printer attached to the network. The inkjet printer and the scanner, however, are attached to individ- ual computers and can be used only locally. A network operating system doesn’t share resources attached to the clients, only resources attached to the network or to the server. Figure 4-2: A client/server network uses only network resources, not local resources. If you want to set up the network in Figure 4-2 to share the inkjet printer and the scanner, you can, depending on the network operating system you use and how you configure your network. Tip Hub Laser printer Color inkjet printer Scanner 56 Part I ✦ Making Basic Network Choices In addition to the client and networking hardware, you need to obtain and set up a server computer. You always should use an uninterruptible power supply (UPS) on the server so that you can shut down the server properly before the power outage affects it. A UPS is a battery backup that keeps your computer running long enough during a power outage for you to save your work and shut down properly. A UPS does not, however, enable you to continue to work after a power outage. Most UPSs last only for 5 minutes or so, just long enough to shut the computer down. Considering server requirements A server computer must have sufficient processor speed, RAM, and disk space to provide various services to the clients. The server’s hardware configuration depends on the type of services it will offer and the number of clients on the network. In addition to hardware, the server needs a compatible operating system. You can use a net- work operating system, or you can use Windows 98 or XP as a server of sorts. (Microsoft has phased out Windows 2000 Professional — a client computer — but they still make a specific network operating system called Windows 2000 Server.) A network operating system supplies more management, security, and other features and tools that make operating the network efficient. Windows 98 or XP as a server operating system limits the services, but might work for your network. See the section in this chapter titled “Looking at Available Network Operating Systems.” Windows 2000 Server (and Professional) requires special hardware to run. You cannot upgrade a Windows 98 computer, for example, with just the operating system. If you pur- chase Windows 2000, it is best to buy a server computer with the operating system installed, so you’ll be sure you have enough power, memory, and other hardware to run the program. The hardware you choose for your server, first and foremost, must be compatible with the operating system. You first should choose the OS you will use and then purchase the server computer. Each OS requires specific amounts of memory and disk space and perhaps certain types of drives — such as Small Computer System Interface (SCSI) or Integrated Drive Electronics (IDE)—and other such requirements. IDE is a popular hard disk interface standard that provides only medium to fast data transfer rates. IDE isn’t always a good interface for server applications because it’s slow and has other limitations in functionality that hamper a server’s operations. You can use an IDE interface in some server circumstances, however, depending on the network operating system (NOS). SCSI, on the other hand, is a high-speed parallel interface. In addition to being fast and extremely practical for server use, you can use SCSI devices to connect a personal computer to as many as seven peripheral devices at a time — using just one port. A port is a socket into which you plug a card, cable, or other device. SCSI devices include hard disks, tape drives, CD-ROM drives, other mass media storage devices, scanners, and printers. You can purchase server computers, complete with operating system, that are built specifi- cally for the job. These computers have all the hardware compatible with the chosen operat- ing system. You might be able to afford a supercomputer, which is a computer that has Note Note Tip [...]... network Tip If you’re currently using Microsoft HomeClick Networking with Windows 95 or 98, upgrading to Windows 20 00 means your upgraded computer will not connect to the HomeClick Network Currently there are no drivers for 20 00 to work with HomeClick Networking (HomeClick Networking was simple networking software Microsoft and 3Com put out to connect Windows 95 and Windows 98 computers.) Using Mac operating... Windows 20 00 Professional Windows 20 00 Professional is the client version of Windows 20 00 Server, even though you can use a variety of clients with 20 00 Server 20 00 Professional is based on NT technology; NT is an early Microsoft operating system for both servers and clients that developed increased speed, multiprocessing, resource sharing, and other networking enhancements NT was so successful, Windows 20 00... example, 20 00 Server records the event in a log so that you can see the time, username, and other information You might not need this feature in your home network; however, if your teenager brings his friends home to work on the computer, you may be glad you have 20 00 Server security Windows 20 00 Server also provides the following features: ✦ Support for remote access — You can dial up your home server... network Using Windows 20 00 Professional is difficult and involved If you’re new to networking and to Windows 20 00 Professional, I suggest you use another operating system to begin your adventure However, if you do succeed in properly setting up Windows 20 00, you can expect increased speed and better performance on the network Tip If you’re currently using Microsoft HomeClick Networking with Windows... computers, installs the software needed, and sets up communication for you Windows Me is an easyto-use workgroup networking operating system Considering Windows XP Home Edition XP Home Edition is another operating system that does not work well with a server XP Home Edition is built for home networking in workgroups As with Windows Me, the operating system is built to recognize a network and communicate... network operating system Using Windows 20 00 Server Windows 20 00 Server is a 32- bit operating system that supports multitasking, which is the simultaneous execution of two or more programs, just as other Windows operating systems do 20 00 Server works well with Windows 98 and XP clients, as well as with Macintosh and Linux You also can use computers running Windows 20 00 Professional (although, as mentioned... protocols for networking, such as NetBEUI or TCP/IP TCP/IP is also known as the Internet Protocol, and it provides high speed on any network For more information about TCP/IP, see Appendix B Windows also supports a wide variety of networking types, logon configurations, user profiles, and more Looking at Windows Me Windows Me is an operating system built especially for home use and home networking Windows... operating system Applications and drivers are abundant for Windows 20 00 Server; however, Windows 20 00 Professional has not taken off the way Microsoft had hoped So drivers and applications might be difficult to find Adding Windows 20 00 as a client brings some extra difficulties into the configuration One thing you’ll need to do is add the Windows 20 00 computer to the network Another thing you must do is create... your house now, such as a Windows 98 computer or an iMac All you need to make a computer into a client is networking software, a network card, and a connection to the server Networking software comes with most operating systems Windows, Macintosh, and Linux all have built-in networking software Networking software includes a protocol (or language) the computers use to communicate with each other, a... can use a 20 00 server with BackOffice to supply your users with every service they need For more information about database management programs, see Chapter 20 Using Novell NetWare Novell NetWare is a 32- bit operating system that runs on Pentium processors NetWare works with a variety of client computers, including Windows 98, Windows XP, and Linux Chapter 4 ✦ Understanding Client/Server Networking . workgroup networking operating system. Considering Windows XP Home Edition XP Home Edition is another operating system that does not work well with a server. XP Home Edition is built for home networking. wide variety of networking types, logon configurations, user profiles, and more. Looking at Windows Me Windows Me is an operating system built especially for home use and home networking. Windows. need this feature in your home network; however, if your teenager brings his friends home to work on the computer, you may be glad you have 20 00 Server security. Windows 20 00 Server also provides