LB's PC Bible Excerpts

(If you'd like to skip the basics, you can go directly to the "Installing a Small Network" quick guide. For a complete set of step-by-step instructions on installing, configuring, using, and troubleshooting a Windows 95/98 Peer network, download my PDF Networking Guide.

Network Basics

So what is a network, exactly? Basically, any group of computers connected to share information. The simplest network is a pair of PCs connected by Ethernet to share files and a printer. The most complex is the Internet, the global network made up of tens of thousands of smaller networks. In this section, we'll quickly go through the basic concepts that underlie the practical tips that make up the rest of this chapter.

Network Design
There are various ways you can set up a network--which makes the most sense depends on how big it's going to be and exactly what you're going to do with it. The easiest way to understand the various approaches to network design is to consider these two extremes:

• Total centralization. In this model, all shared resources reside on dedicated servers, PCs dedicated exclusively to providing services to the other computers on the network. Dedicated file servers hold shared applications and data; print servers run shared printers; database servers run multiuser databases; gateway servers handle Internet access--you get the idea. Often a single PC plays multiple server roles. The servers, which no one touches except the network administrators, run industrial-strength operating systems like Novell NetWare, Windows NT Server, or Unix, which have features that allow all the other computers on the network to talk with each other, share files, and to access the Internet.

• Total decentralization. Shared applications, data, and printers can be located on any PC on the network; to put it another way, any PC can share its hard drive and printer with any other PC. Since each PC has an equal chance of being a server, this model is often called peer-to-peer networking. Windows 95, 98, and NT Workstation all have this kind of network capability built in.

In reality, larger networks are almost always a hybrid of these two models. Small networks like the ones we're focusing on in this chapter are sometimes purely peer-to-peer, but sometimes there are good reasons to use dedicated servers even on the smallest networks--for instance, if you've got a multiuser accounting package, you'll probably want to give it its own PC. See "When Do You Need a Dedicated Server?" later in this chapter for details.

Ethernet Hardware
A thorough discussion of the variety of network hardware currently in use could fill a book larger than this one, but for our purposes that's of only academic interest. Unless you're a network professional working for a large organization, the only kind of hardware you're likely to encounter is Ethernet. Here are the various components you'll need to build a basic small network.

• Adapters. A PC is connected to the network by its Ethernet adapter, a device that converts data into signals suitable for sending over the network's cables. Reliable adapter manufacturers include 3Com, Intel, Novell/Eagle, Hewlett-Packard, Xircom, and Standard Microsystems/Western Digital (SMC). You can get both ISA and PCI models; which makes most sense for you depends primarily on how many free slots you have and what other expansion cards you might want to install in the future. All else being equal, I recommend PCI.

• Cables. These days, the most popular flavors of Ethernet for PCs are 10BaseT and 100BaseT (a.k.a. Fast Ethernet), which use the same kind of wire telephones use but have slightly larger jacks and plugs (see Figure 1). Take care not to accidentally plug a telephone line into an Ethernet jack, as that can damage your equipment. In a small network, cables run from each PC's adapter to a central hub. In a large or older network, you may also encounter the old "thinnet" style of Ethernet. These adapters were usually daisy-chained by 3/16-inch round cables running from one to the next, like lights on a Christmas tree, though thinnet cables can also be connected to compatible hubs.

 

Figure 1 .......................... 10BaseT cable and RJ-45 jack.

• Hub. In a small network, this is usually a small box, about the size of an external modem or paperback book, with a row of Ethernet jacks (also called "ports") on one side and, preferably, a few status lights for troubleshooting connection or performance problems (see Figure 2). Hubs start at under $100 for four-port models, and the price goes up as you add ports. More expensive hubs usually include an uplink port to connect to another hub, so when you've used up all the ports on one hub you can add another and keep adding PCs to your network indefinitely. On big networks, hubs are often mounted in racks, have all sorts of fancy features, and may have hundreds of ports.

Figure 2
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A typical network hub for a small business.

 

• ISDN router. An ISDN router is a good alternative to a standard hub. One of these boxes, which start at around $300, combines an Ethernet hub with an ISDN adapter that all the PCs on the network can share. (ISDN is a digital telephone line that gives you an Internet connection that's three to four times as fast as a V.90 modem. See Chapter 19: Getting On the Internet, for more details.)

For a small network, you need an Ethernet adapter for each PC, a hub or ISDN router with at least one jack for each PC, and cables to connect each PC to the hub. If you've got only two PCs, you don't need a hub: you can just connect the two directly. Note that a regular Ethernet cable won't work in that situation: you need a specially wired direct-connect cable.

If you're starting a new network from scratch, I recommend you use 100BaseT Ethernet hardware, which is much faster than the old 10BaseT products. The adapters cost about the same, and the faster hubs are only a little more expensive. Note that you can't use both 10BaseT and 100BaseT adapters on your network unless you have a dual-speed hub specifically designed to support such mixing.

It's generally best to buy adapters and hubs from established names in the industry, such as Xircom, Hewlett-Packard, or 3Com. The prices may be slightly higher than for "no-name" or off-brand models, but you have a reasonable guarantee that the stuff will work properly right out of the box, the first time you install it.

If you need reliable network cards and a hub to set up a small business network with a minimum of hassle, 3COM's starter kits are a good choice. Founded 20 years ago by Bob Metcalfe, the guy who invented Ethernet, the company has a reputation for dependable performance. The entry-level 4-Port Office Connect Networking Kit (around $110 on the street) includes everything you need to connect two PCs: two 10BaseT adapters, two 25-foot cables, and a four-port 10BaseT hub, which gives you room to add two more PCs later. More expensive bundles include 8-port hubs and/or 100BaseT hardware. All the kits ship with the OfficeConnect Network Assistant CD-ROM, a helpful step-by-step guide to setting up and using a basic network.

Network Protocols
If you think of your Ethernet adapter as a mailbox and its hub as the central post office, transport protocols are the ZIP code system the network uses to tell where data's supposed to end up. When your PC sends a file across the network, it encodes the data into packets that bear distinctive destination signs. Actually, it's more complicated than that, since thanks to the anarchic evolution of PC networks there are a number of different protocols in common use, and there's a good chance your PC uses more than one of them.

You don't really need to know anything about protocols to use them. However, since you may see them in a dialog box and wonder what the alphabet soup's all about, here's a brief explanation of the three supported by Windows, plus one that comes into play if you've got Macs:

• TCP/IP. (Transport Control Protocol/Internet Protocol). The standard for the Internet, this protocol is increasingly popular on private networks as well, both to handle access to the Internet and to provide Internet-style local services, like in-house Web sites.

• IPX/SPX. The proprietary protocol used by Novell NetWare. It's a very efficient protocol for use with file servers, which is NetWare's forte. Generally, there's no need to install this protocol if none of the systems on your network are running NetWare, though there are occasional exceptions: the Direct Cable Connection utility, for reasons known only to Microsoft, uses it.

• NetBEUI. Microsoft's proprietary protocol. If you don't make a special effort to configure your network differently, this is what will be used for local services, like sharing hard drives and printers.

• AppleTalk. Macintosh computers use this proprietary protocol. Windows NT Server supports it, at least to the extent necessary to let Macs access files and share printers. (Apple formerly used the term AppleTalk to refer also to the low-speed network hardware that Macs once used, but when the company switched to Ethernet hardware it renamed the old hardware LocalTalk.)