In this chapter:
Think networking is difficult to understand? Think again. After all, it's just sharing...
In the office, you probably share documents all the time. So how can you send your version of a file to someone else for her comments? One way is to copy your file to a floppy disk, stick it in a manila envelope, put it in your outbasket, and wait a few days for the revisions to work their way back to you. Not a very practical solution, is it? Wouldn't it make more sense if you could somehow hook your computers together so you could both work with the same file whenever you need to?
That's the idea behind computer networks. With the help of a little bit of extra hardware (and a lot of wire), you can extend the reach of your computer to share files, folders, and printers--instantly. Computer networks can stretch around the world, or they can be as small as two PCs sitting side by side on the same table. No matter how big or small your network is, you can work with it easily once you learn the basics.
In general, networks help you and your company get more productive use out of the hardware you own. Networks also let you and your coworkers keep data locked up by assigning passwords and defining permissions so that only the right people can get to it. There are slightly different techniques for sharing (and securing) files and printers on different kinds of networks.
Nearly every kind of network lets you share files on a central computer called a file server. As long as you know the name of the file server, and your network administrator (the person who runs your network) has set up the network to allow you to access it, you can read and write files on folders on the file server. Depending on the kind of network your company uses, you may also belong to a workgroup--a (usually) smaller assortment of users connected to one file server on the network. A bank, for example, might choose to create workgroups called Admin, Mortgage, and Collections, each with its own file server.
Finally, if your company uses Windows NT on its file servers, too, you'll probably belong to a domain, which is a (usually) larger collection of workgroups and servers. Grouping users this way makes it easier for administrators to manage all those computers. Because all the user names and passwords in the domain are stored in a central location, domains also make life easier for you if you move from office to office as part of your job--you can log on from any computer and know that the Windows network will recognize you.
Have you ever used interoffice mail? Then you already know the fundamental principles behind computer networking. When you want to send a printed report to someone else, you slip it into an envelope, write the recipient's name on the To: line, put your own name on the From: line, and put it in your outbox. The next time the mail-room guy passes by on his rounds, he picks up the envelope and delivers it.
Your company's computer network handles files in much the same way.
Each PC on the network uses a piece of software called a network client to chop files into small pieces called packets. (You might have to do the same thing with a thousand-page printed report if your envelopes can only hold 100 pages at a time.) The client software on the sending end stuffs each packet into the electronic equivalent of a manila envelope and adds the To and From information, plus details about how to put the file back together ("This is packet #6 of 32"); the client on the receiving end opens all the envelopes and reassembles the pieces into a file that looks just like the one that was sent. (This all happens quickly and invisibly, of course.)
Every computer on the network has a plug-in card called a network adapter. It's easy to spot the adapter--that's where the network cable is plugged into your PC. It functions something like a combination in- and out-basket, since every packet that comes into or out of the computer has to go through this piece of hardware.
For your computer to successfully send envelopes full of information across the network, it has to use the same protocol as the rest of the computers on the network. No, it has nothing to do with which fork you use at a formal dinner party; a protocol is simply the language that your network speaks. Protocols generally have tongue-twisting acronyms like IPX/SPX or TCP/IP instead of plain-English names. (Puzzled about how to pronounce these catchy acronyms? There's nothing fancy involved. Just ignore the slashes and pronounce each letter in turn.)
Finally, your network may allow you to add services such as file and printer
sharing. With the right service installed on your networked computer, for example,
you can give someone else permission to send documents through his network adapter,
across the cable, into your network adapter, and ultimately to your printer or onto
your hard drive. Needless to say, you'll want to think carefully about the consequences
before you let someone share your PC or printer!
You'll sometimes hear people refer to their network as a LAN or WAN. What's that all about? LAN stands for Local Area Network. As the name implies, a LAN is usually concentrated in a single location, and most of the machines are connected with wires. A WAN, which is short for Wide Area Network, consists of two or more LANs, usually joined together by high-speed telephone lines. In big companies, it's not surprising to see WANs that tie together people in different states and even different continents.
The same is true for printers. Instead of buying an expensive laser printer for every
employee, your company can buy one fast, powerful printer for each department, hook
all the printers to a network, and let the employees in each department use the one
that's closest to them.
On some networks, you can let other people share a folder on your own computer's hard drive so you can both get to the files anytime. And Windows NT even includes a program called Chat, which lets you converse with your coworkers by typing messages into a shared window; you can use Chat to carry on the equivalent of a conference call, or just to goof off while everyone around you thinks you're working hard.
If you're connected to a network, you'll find an extra icon on your Windows desktop. Just as My Computer contains everything that's inside your personal PC, the Network Neighborhood is filled with icons representing everything your computer is connected to. Figure 20.1 is a representation of what I see when I double-click on this icon.
Here's what you'll find inside:
Fig. 20.1
You and your immediate neighbors show up in the Network Neighborhood. If you want to see everything that's available on your network, double-click on the Entire Network icon.
NetWare is a popular network operating system sold by Novell Corp. of Salt Lake City, Utah. If your company has a network today, chances are good that there's at least one NetWare file server somewhere on it, because this has been the standard operating system for corporate net- works for many years. UNIX, which comes in dozens of varieties from all sorts of different companies, is the operating system of the Internet. It is widely used in universities and on high-powered graphic workstations. Windows NT was specifically designed to cooperate with these and other popular networks.
Some or all of the PCs on your network get their own icons in the Network Neighborhood. Dig a little deeper and you can see whether the owner of that PC has put the Windows equivalent of a "Share Me" sign on any of his folders or printers. For example, if Bob in Accounting wants you to look over this month's payroll report, he could put the report in a folder, call it Payroll Reports, and tell Windows that it's OK if you look at it. Now, when you explore the icon for Bob's PC in the Network Neighborhood, you'll see that shared folder as well.
If you're on a network, you have to identify yourself to the network every time you turn on your PC and start Windows. There are a variety of Windows logon screens, depending on which kind of network your company uses. (See Fig. 20.2 for an example of one such dialog box.)
Fig. 20.2
Every time you turn on your computer, Windows asks you to log on by entering your user name and password.
Logging on does two things. The process sends your user name and password to any file servers on your network so that you can have access to files stored there. It also tells Windows which user profile belongs to you.
As you'll recall, your system administrator originally set up your PC so that more than one person can use it; at a minimum, there's an account for the system administrator and for you. User profiles keep track of the different settings for each user. For example, you can arrange the icons and wallpaper on your Windows desktop and the choices on your Start menu exactly the way you want, without being concerned that someone else who uses the same PC will rearrange things. User profiles also set aside completely separate areas on the computer where you and other users can store private files without worrying whether someone else will read them or, worse, delete them.
You can change your Windows NT password by pressing Ctrl-Alt-Del. Everything on your screen will disappear (don't worry; it will all come back when you're done) and you'll see the Windows NT Security dialog box (Fig. 20.3). Windows asks you to enter your original password (to prove you are who you say you are) and then enter the new password. If you want to change your password for another network, such as NetWare, ask your network administrator for help.
Easy. Whoever set up your network account entered some information in a dialog box like the one in Figure 20.3.
Fig. 20.3
Use this dialog box to change your password. Make sure you pick something that a stranger won't guess easily.
Fig. 20.4
Name, rank, and serial number? The Network properties dialog box tells Windows your computer's name and the name of your workgroup or domain.
You already entered your user name when you logged on to the network. (The user name is usually some variant of your first and last name, although it can be any name or even a string of letters and numbers that looks like nonsense.) Windows uses this information to look up your network rights and desktop preferences.
Your computer also has a name that other people need to use when they connect to any folders or printers you've set up for sharing. The system administrator defined this name when he or she first set up Windows on your computer.
Why one name for you and one for your computer? Well, there's no reason why two or more people can't use one computer, with different mailboxes and desktops and other personal preferences. But no matter who's using the computer, its resources--such as hard disks, CD-ROM drives, and attached printers--will always remain the same. Identifying users by user name guarantees that mail will get to the right place. Identifying computers by computer name makes it easy for anyone who wants to share a resource to find it quickly, regardless of who's using it.
Do you want to change the name of your computer or your user account? Sorry, you can't do it yourself, unless you can log on as a system administrator. There's a good reason for this restriction: If either name changes without warning, other people on the network may not be able to find the resources they're looking for, when they need them.
Networking gets more complicated (but not necessarily more difficult) when you mix and match different network operating systems. At my office, for example, we have a mix of Windows NT and NetWare file servers, all of them used by different workgroups for different tasks. In some cases, my Windows user name and password are sufficient to grant me access to the files and folders and printers connected to the NetWare server. In other cases, I need to remember a separate user name and password to log on.
It's no different from the way the security system in my office building works. My electronic card key lets me unlock doors on my floor, but on other floors, run by other companies, I need a different key (and special permission) before they'll let me in the door.
On networks that include NetWare file servers, you (or your network administrator) will need to use the Client Service for NetWare, found in the Control Panel. When you double-click this icon, you'll see a dialog box like the one in Figure 20.5. The most important setting here is the one for your preferred server. That setting tells Windows where to send the user name and password you enter, so that you can have permission to use Netware resources.
Fig. 20.5
If your company uses NetWare file servers, you (or your network administrator) need to tell Windows which server has your logon information.
Before you can use files and folders on a NetWare server, you first have to attach to the server--that's NetWare's term for what Windows calls logging on. If the server is your preferred server, this happened automatically when you logged on to Windows NT. If you need to use another NetWare server, just browse through the Network Neighborhood, find the appropriate server, and double-click on its icon. You'll see a dialog box like the one in Figure 20.6.
Why enter a user name? Doesn't Windows remember your user name? Well, yes, but when you connect to a new file server you may be expected to use a different name. For example, my company uses a NetWare server to give every employee access to a collection of CD-ROMs stored on a big jukebox-style drive. There are no sensitive files stored here, and because CDs are a read-only medium, there's no risk that someone will accidentally delete a file. So, to log in to this server, every user enters the same user name and password. That way, the network administrator doesn't have to manage a long list of users.
Fig. 20.6
When you double-click on a NetWare server, you may be asked to enter a user name and password.
What should you do when you're finished using resources on a NetWare server that isn't your preferred server? Your network administrator would be very grateful if you logged out. You see, the total number of connections to a file server is limited, and if you remain attached to the server after you've completed your task, you may lock out another user who needs access to the same resources.
To disconnect from a NetWare server and free the connection for another user, right-click the server's icon and choose Log Out. As you can see from Figure 20.7, Windows will warn you that you're about to lose contact with the shared resources on it. If you're sure this is what you want to do, click OK.
Fig. 20.7
When you right-click on the icon for a NetWare server, you have the option to log out and free the connection for another user.
I'm not trying to get philosophical here, really. But when you want to find out which NetWare servers you're attached to, under which user names, just right-click the Network Neighborhood and choose Who Am I from the pop-up menu. The NetWare Client Service will respond with a dialog box like the one in Figure 20.8, telling you the name of your preferred server, along with the user names you've used to attach to any additional servers.
Fig. 20.8
It's not exactly the Meaning of Life, but the Who Am I command will at least tell you who the NetWare Client Service thinks you are.
There are lots of good reasons to store your work on a file server. Most of the time, you'll store data files on the network because it makes it easier for a group of people to share the workload--an annual report that you and a team of coworkers are updating, for example, or a consolidated budget spreadsheet with a different manager responsible for each page.
To use files your own computer, you double-click the My Computer icon. To use files on another computer, you have to go through one extra step.
Just as on your own computer, you can open or save files on any computer to which you're networked--just point and click. Start in the Network Neighborhood, double-clicking the name of the computer you want to use, and then work your way through the shared folders until you find the place and name you want. You can even do this using the File Open and File Save As dialog boxes when you save a document, as shown in Figure 20.9.
On your own computer, you're used to referring to disk drives by letter, such as A: and C:, for your main floppy and hard drives. With some programs, drive letters are the only way to use files; these programs (mostly older DOS and Windows programs) won't let you point and click your way through the Network Neighborhood. Instead, you have to fool Windows into using a drive letter for one of these shared folders. The process is called drive mapping--as the phrase suggests, you're creating a "map" of network locations, each one labeled with a drive letter, that Windows can refer to when you use one of the mapped drive letters. Here's how:
Fig. 20.9
Use the drop-down list in the File Open and File Save As dialog boxes to work with a file on another computer somewhere in the Network Neighborhood.
Browse through the Network Neighborhood until you reach the folder you want to use. Right-click the shared folder, and choose Map Network Drive. (Fig. 20.10 shows the dialog box.) Notice that the computer name and folder name are already filled in. You'll see a slightly different version of the same dialog box if you right-click the My Computer icon and choose the Map Network Drive command.)
Fig. 20.10
Use this dialog box to tell Windows where in the Network Neighborhood to look when you use a specific drive letter.
The complicated strings of text in the drive-mapping boxes are called UNC names. Just as you can refer to locations on your computer with a drive letter, a colon, a backslash, and a folder name, you can refer to locations on another computer by typing its full name. A UNC name starts with two backslashes, followed by the computer name, another backslash, the name of the shared folder or volume, another backslash, and so on.
Here's how it works: Let's say your company has a file server named Calvin on which the network administrator has defined a shared folder named Data. The Data folder in turn contains a folder called Letters. You can get to the Letters folder (in a File Save As dialog box, say) by typing its full UNC name:
Plain English, please!UNC means Universal Naming Convention. That's a fancy designation for an agreement between different network software makers. UNC names allow you to connect to any file server, even when you don't know exactly what kind of network operating system the file server is using.
When you're working in an office as part of a team, you'll find plenty of productive ways to use Windows' built-in sharing features. On a Windows network, you can set aside a portion of your hard drive (or all of it, for that matter) as a sort of lending library. Anyone else on the network can stop by and browse through the contents at their leisure.
If security's an issue, you can have Windows assign a librarian to monitor the shared area and demand some ID, in the form of a password, before letting a stranger in. Windows lets you share printers and CD-ROM drives, too.
You might share your entire hard drive with a trusted administrative assistant; that way, every time either of you wanted to use the files on your hard disk, they'd be right there. Or you could give a coworker the rights to look at just one folder filled with documents you're collaborating on. The documents themselves remain on your hard disk while Windows' messengers shuttle them across the network wire on demand.
Before you can share anything on your PC with other users on your company's network (or stop sharing it), your administrator has to grant you that permission. If you've been assigned to the built-in Windows NT Power Users group, you already have this right. If, on the other hand, you've been assigned to the less privileged Users group, you'll be able to see access restrictions on files you create, but you won't be able to change them. For more information about users and groups, see Chapter 3.
Assuming you have the right permissions, sharing files and folders with others on your network is a simple process:
Fig. 20.11
Right-click a drive or folder and choose Sharing to reveal this dialog box. Click Permissions to fine-tune who gets access to what.
When you click the Permissions button, you'll see one of the most confusing dialog boxes in Windows NT. (To follow along, look at Fig. 20.12.) Believe it or not, NT assumes, when you share a drive or a folder, that you want to give everyone in your entire network full control over that file. They can read it, change it, rename it, even delete it completely!
If that's not what you intended, change the options in the Access Through Share Permissions dialog box.
Fig. 20.12
Do you want anyone to be able to poke around in your files--and even rename or delete them? If not, then change the Type of Access for the Everyone group from Full Control to Read.
To share a printer, open the My Computer folder, double-click on the Printers icon, highlight the name of a printer, and follow the same steps.
When you browse through the Network Neighborhood and double-click on the icon for a PC, you'll see an icon for each shared folder and printer that's available. To open the shared folder, just double-click. If the owner of that computer has assigned a password, you'll have to enter it here before you can see what's available.
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