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The Complete Idiot's Guide to Networking
- 3 -
Tried and True: Networking the Ethernet Way
In This Chapter
- How an ethernet network works
- Choosing the right pieces
- Installing your network
- Ethernet options: With or without a hub
The most popular type of network in existence today is ethernet, whichis a standard way of connecting two or more computers. Because it is the prevailingstandard for computer networking, ethernet products are interoperable. (Thisis just a geeky way of saying that ethernet products you buy from one manufacturertend to play nicely with ones that you buy from another manufacturer.)
Because you are setting up a new home network, this isn't such a big deal. Asa rule, people starting something from scratch tend to buy everything from the samemanufacturer. But, like the hula-hoop and the Rubik's cube, networking manufacturerscome and go. That ethernet card you buy today may not be available in a few years--worseyet, neither will the company that manufactured it!
Another big benefit of ethernet is its scalability, or the measure of itscapacity to cont inue to meet your needs as the network grows. Ethernet is a highlyscalable network technology in terms of both the size and speed of networks thatit can support. For example, networks with 100 ethernet-attached computers are common.
Probably the single largest drawback to ethernet--particularly in a home network--isthe fact that every device on the network must have a cable that plugs into it. Forthe semi-serious home network enthusiast, this usually means a basement office thatends up looking like the snake pit scene from Raiders of the Lost Ark. Youcan overcome this downside with some planning and, depending on the size of yournetwork, a few strategically placed holes in your walls.
Shopping for Your Ethernet Network
Like all shopping trips, the best place to start is with a good grocery list.Take a look at the following list for a rough overview of the pieces that you needto buy to get started with your home network:
- Computers Although there are many reasons for wanting an ethernet network in your house, none is as compelling as the fact that you have two or more computers to share information and resources between.
- Ethernet card This little guy acts as the middleman between your computer and your home area network. It plugs into an unused slot on your computer's motherboard. After the ethernet card is properly installed in your computer, you need to plug an ethernet cable into it from outside the computer. You'll need to buy one ethernet card for every computer that you want to put on your network.
- Ethernet cards connect a computer to the home network.
- Ethernet driver This is a small piece of software that your computer needs to be able to talk to your ethernet card. Unless you have a very old card, your operating system probably has a driver for it. If not, you'll have to use the disk supplied with the ethernet card you bought to install it yourself. More on this process later.
- Ethernet cable Just like your VCR must connect to your TV so that you can watch taped reruns of Gilligan's Island, every computer on your network must have some way of connecting with the rest of the network. Ethernet cable is that connector.
The two most common types of ethernet cables are Category 5 Unshielded Twisted Pair and 10BASE-T coaxial cable. These are more commonly referred to as Cat 5 and coax. Cat 5 cable is used to create star networks with an ethernet hub (see the following figure). Coaxial cable, on the other hand, does not require a hub.
Because Cat 5 networks are easier to install and maintain, most network kits use Cat 5 cables and ethernet hubs. For a simple network, such as one that has two computers connected in the same room, coax is a cheap and easy solution.
- An ethernet hub As mentioned, each ethernet card has a matching ethernet cable. Each ethernet cable plugs into a computer on one end and the ethernet hub on the other. In this way, your ethernet hub forms the center of your network, passing information from each device to all other devices. By si tting in the center of your network, the hub also serves to protect and isolate each of the cables and cards on your network from one another.
Buying a Hub
Count up how many ethernet cables you are going to have in your network and make sure that the hub you buy has at least as many connectors as you have cables. Better yet, make sure that you have a few left over in case you add more computers next year. That idea might make you laugh now, but if somebody had told you five years ago you'd be reading a book on how to network your house, you probably would've told him or her to have another drink.
Ethernet hubs are compact and easy to use.
- Other ethernet devices Computers aren't the only devices that can plug into an ethernet network. Many types of printers can be connected directly to a network as well, enabling you to print to them without having to rely on a computer to drive your printer for you. Another network device growing in popularity provides a high-speed connection to the Internet. If you're lucky enough to live in an area that has them, cable modems and their telephone-company cousins ADSL modems both come ready to connect directly to your ethernet network.
Check This Out
We'll talk more about cable and ADSL modems in Chapter 7, "You've Got the Whole World in Your HAN: Connecting to the Internet."
Pick a Card, Any Card: Which Network Card Is Right for You?
With a gazillion network cards on the market, it's sometimes difficult to figureout which one is right for you. Here are a few things to consider:
- Plug and Play Plug and Play is a Windows 95/98 capability that makes it easy for you to add new hardware to your computer. If you plan to run a Windows network and the ethernet card you are considering purchasing does not support Plug and Play, do yourself a favor and reconsider.
- Cost Ethernet cards are, for the most part, quite cheap--about $50 to $70 per computer.
- Speed Ethernet can transmit up to 10 megabits per second (Mbps) across your network. This is generally fast enough for home networking. If you are going to be moving large files on a regular basis, or if you are considering testing videoconferencing or other high-capacity network services across your network, consider fast ethernet, which operates at 100Mbps. Watch out for the price, though; a fast ethernet home networking kit will cost you about twice as much money as a comparable ethernet kit.
Using the Card You Already Have
As networking has grown in popularity, many computer manufacturers have startedshipping models with ethernet capability already installed. Although manufacturersmight not include an actual ethernet card in the computer, they may have one builtin as a part of the computer's motherboard. Talk to a representative at your computerstore, or check your computer's documentation if you're not sure.
If you are considering buying a new computer and you know for sure that you wantto use it on a network, a sk your computer store about its options for built-in ethernet.You may find that it saves you a few dollars (and a few fiddly moments with a screwdriver)over buying and installing a card yourself.
Save Some Cash: The Home Network Kit
If you want to save a few bucks, check out the all-in-one network starter kits. The most basic models typically include two ethernet cards and a four-port ethernet hub. These will run you $120 to $150. If you need a little more room to grow, an eight-port hub with three ethernet cards will set you back about $225.
Installing Your Ethernet Card
You knew it was going to come to this. Sooner or later, you were going to haveto roll up your sleeves and crack the box on your computer. Every computer is a littledifferent, but the general idea is the same. Here's what you do:
- 1. First things first, turn the computer off. There's no use turning your computer into a planter by zapping it with an electric shock while trying to open it. In addition, leave the computer plugged in to keep it grounded. If you have to unplug it to bring it to a place where you can work on it, that's no sweat--just make sure that you put it down in a relatively static-free environment. In other words, leave the wool sweater in your closet and avoid letting your cat crawl around inside the box after you have it open.
2. Take a look at the screws on the back (or, depending on what type of computer you have, on the side or the front) and pick an appropriate screwdriver from your collec tion for the task. The most common screw used to hold computers together is a Phillips, otherwise known as "that funky star-shaped one."
3. After you get the screws out, the cover should slide off slick as a whistle. Of course, pigs fly, chickens have lips, and Bill Gates still balances his own checkbook. If you're still having trouble breaking in, make sure to check your computer manual. It'll help you identify that one nasty screw hiding beneath the Intel Inside sticker on the front of the case.
4. After you manage to wrestle the cover off the case, take a look around inside for empty slots that look like they match your card. If you're not sure, close your eyes and let The Force guide you. Alternatively, you could use the cards already installed in your computer as a guide.
5. Before trying to insert your ethernet card into the slot, make sure that you remove the little protective plate that's screwed into the computer behind it. The plate looks like an aluminum tongue depressor with a screw hole in it.
6. Being careful not to accidentally unplug any of the cables snaking around inside your computer, gently insert the ethernet card into the slot until you are sure that it's lined up right. Then, push a little harder until you feel a reassuring sshhunk!! as the card slides into place.
7. Don't forget to screw the ethernet card's back plate on, because cards have a tendency to work themselves out of the slot over time if you forget.
8. Firmly close your eye s and try to picture the place where you left the screws for the computer's case (that place where you told yourself you surely wouldn't forget). Got it? Good! Go get the screws and put the case back together.
9. Turn your computer back on.
- This diagram of a motherboard shows how an NIC fits into a slot.
When Plug and Play Doesn't Play Nice
Plug and Play is a feature of Windows 95/98 (and soon to be Windows 2000) thathelps you install new hardware into your computer with minimal pain and aggravation.Although it occasionally makes mistakes, Plug and Play can be your best friend whenyou first start adding new cards to your computer.
If you used a plug-and-play ethernet card and everything goes the way it should,your computer will detect that the new hardware has been added to the computer whenyou turn it on. After detection, the computer will install the appropriate driverfor your ethernet card and return you to the Windows desktop. If this happens, you'reready to move on; if not...Plug and Play isn't playing nice. There are a few thingsthat could be wrong:
- You have an older ethernet card that doesn't support plug-and-play installation. If this is the case, after you have installed the card in the slot, you will have to configure the card manually.
- Plug and Play has let you down and failed to detect the card. Although this is a heinous crime worthy of jail time for a Microsoft programmer, it's not unheard of. In such a case, you'll need to configure the card manually.
Manually Configuring Your New Ethernet Card
If Pl ug and Play lets you down, meaning that you have to configure your networkcard yourself, do the following:
- 1. Select Start, Settings, Control Panel, Add New Hardware.
2. Read the instructions on the screen and click Next.
3. Read some more instructions and click Next. Windows searches through all available hardware to see whether any new plug-and-play devices can be detected. As per the instructions, you should let Windows see whether it can find your new ethernet card, even though it's not Plug and Play.
4. Windows should find your new ethernet card and allow you to install a driver.
5. Use the disk that came with your ethernet card if you have one; this is because the driver that came with your ethernet card is most likely more current than the driver that came with Windows.
Device Not Found
If for some reason your computer does not select your ethernet card, consult your ethernet card manual for instructions specific to your card.
IRQs and You
IRQ is an acronym that strikes fear into the hearts of many computer users,novice and professional alike. The confusion starts with the name itself. IRQ isan acronym for Interrupt ReQuest line; the way the acronym is derived shouldconvince you that this particular computer concept was thought up at a time whendrug use was rampant in the computer industry.
IRQs are like little traffic cops in your computer. They give the right to eachof 16 different d evices in your computer to hold up their hand and say to the CPU,"Hey, it's my turn to talk." Each device is assigned its own IRQ, whichyour CPU uses to refer to it. Things go haywire when two devices in your computerboth try to use the same IRQ to interrupt the CPU. The CPU doesn't know which oneto listen to, and it keels over. At best, the two devices will stop working; at worst,your computer decides to take a siesta until you resolve the conflict.
Resolving the conflict means figuring out which devices in your computer aren'tplaying nice. The easiest way to see which devices are using which IRQ is to clickStart, Settings, Control Panel, System, and thenselect the Devices tab. Finally, double-click the Computer icon inthe upper-left corner.
Make sure that the IRQ button is selected; you should see a list of allthe IRQs from 00 to 15. (Don't you just love computer geeks! Who would have thoughtthat you could count to 16 by going from 00 to 15?)
If you find yourself in a position where you have to change IRQs or other settingson existing equipment to get your ethernet card to work, congratulations. You haveofficially exceeded the scope of this book. Although not extremely difficult to do,this is one place where you may want to call in your nephew Phil, the computer geek,to come and give you a hand. This is because incorrectly configured IRQs can keepyour computer from rebooting, making it difficult to troubleshoot problems that youaccidentally generate while trying to fix your problem. If you don't have a Philat your disposal, the store where you bought the ethernet card may be able to helpyou with the installation. P>
To Hub or Not to Hub...
As discussed in detail in Chapter 2, "From the Bottom Up: The Foundationof Your Networked Home," there are several different possible network layouts.Point-to-point and star networks are the two that you will find most useful for thehome. Either one can be used, but one will be better than the other, depending onthe size of your network.
Networking Without a Hub
A point-to-point network is useful if you plan to have only two computers on yournetwork. This type of connection requires a special ethernet cable that you can pickup from your local computer store called a crossover cable. The crossovercable allows you to connect your two computers from the ethernet port on one computerdirectly to the ethernet port on the other. Cheap? Yes. Easy? Yes. Limited? Absolutely!
By going from ethernet card to ethernet card, you have created a hublessnetwork. It will be difficult--if not impossible--to add a third computerto the network. If you think you'll ever grow beyond two computers, consider addinga hub to the center of your network.
Networking with a Hub
Every ethernet cable on your network should plug into the hub. Positioned at thecenter of the network, the hub's job is to pass information from every networkeddevice to every other networked device.
- This diagram shows a four-port ethernet hub plugged into two computers.
KISS: Keep it Simple, Silly
Although it is possible to mix different-speed ethernet cards on the same network, it is easier (and cheaper) if yo u choose which speed you want and purchase the hub and ethernet cards to match.Although it is possible to mix different-speed ethernet cards on the same network, it is easier (and cheaper) if you choose which speed you want and purchase the hub and ethernet cards to match.
The Wiring Closet
The place where you choose to put your ethernet hub should be easy to get at and relatively free of clutter. In your closet underneath the clothes hamper is not recommended.
Selecting a Hub
The most important thing to remember about selecting a hub is that it must matchthe speed of the ethernet cards you want to use. There are several different typesof ethernet, ranging in speed from 10Mbps to 1000Mbps:
- Ethernet, often called 10BASE-T, operates at 10Mbps. It is the oldest form of Ethernet and is, therefore, very reliable. The speed of this network should be enough for most home users, but if you transfer huge files across your network, you might want to consider fast ethernet.
- Fast ethernet, often called 100BASE-T, operates at 100Mbps. Although newer than ethernet, fast ethernet has been in use for a few years now and is stable enough for use in your home network. You'll have to work long and hard to think of something to do on your network that will push fast ethernet to its limits.
- You've decided that you just can't survive without the latest, greatest, and fastest. Never fear! Gigabit ethernet is here! Operating at a whopping 1Gbps (that's 1000Mb, folks), gigabit ethernet has more speed than you'll ever need. Beware, t hough: As a cutting-edge technology, gigabit ethernet comes with a cutting-edge price as well as a few cutting-edge problems. Only bite into gigabit ethernet if you have the time and the money to do it right.
If you decide at a later date to connect to the Internet with another type of connection (such as a cable modem, ISDN, and so on), you're not going to be able to do it with the modem built into your new hub. If you use one of these alternative methods to connect to the Internet, you should forego the built-in modem and stick with a plain ethernet hub.
Integrated Modems and Ethernet Hubs
Recently, ethernet hubs have begun to appear with modems built right in. Thisfrees the modem from being connected to a specific computer--in effect, putting themodem directly on the network. Although there are other ways to do it (hint: checkout Chapter 7), these devices offer a quick and painless solution for connectingevery PC in the house to the Internet with a single modem.
Although it is possible to mix different-speed ethernet cards on the same network,it is easier (and cheaper) if you choose which speed you want and purchase the huband ethernet cards to match.
The Least You Need to Know
- Ethernet is a mature scalable form of networking that is well suited to the home.
- On the downside, depending on the size of your network, a few strategically placed holes in your walls will be required.
- You should now be comfy with the hardware and software that you will need to get your ethernet network up and running. Even better, you should now be ready to try to do it yourself!