The Complete Idiot's Guide to Networking
[Figures are not included in this sample chapter]
Chapter
- 3 - Tried and True: Networking the Ethernet Way
In This Chapter
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How an ethernet network works
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Choosing the right pieces
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Installing your network
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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:
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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.
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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.
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Ethernet cards connect a computer to the home network.
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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.
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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.
Cables
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.
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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.
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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:
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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.
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Cost
Ethernet cards are, for the most part, quite cheap--about
$50 to $70 per computer.
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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:
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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.
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This diagram of a motherboard shows how an NIC fits into a slot.
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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:
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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.
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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:
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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.
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.
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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:
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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.
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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.
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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.
Note
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
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Ethernet is a mature scalable form of networking that is well suited to
the home.
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On the downside, depending on the size of your network, a few
strategically placed holes in your walls will be required.
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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!
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The Smartest DIY Home Improvements
