NETWORK BASICS:

A computer network is created by connecting PCs together via cables, connecting hardware, and network software components (this software is built into Windows).  Networks allow the connected computers to share data, software and resources.  Computers which are linked together on a network can:

• Exchange files and documents internally. 
• Share hard disk space and other drive resources (floppy, CD-ROM, tape backup, etc.)
• Print to shared printers
• Share an Internet connection
• Provide communication (email, audio and video conferencing, network-based fax services, etc.)
• Enable remote control of connected hardware devices (entire offsite computers, cameras, devices installed as expansion cards and peripherals, etc.)
• Run software installed on a separate machine
• Provide data collection, manipulation, use, and storage between machines

Networks have become commonplace in mainstream home/business computing.  Broadband (fast) Internet connections are now prevalent in many homes, and most business computing systems make use of a connected network of machines. The Internet itself is a large network which average computer users make use of on a daily basis.  The concepts involved, and the configuration steps required to setup your own network are very simple.

This lesson will cover basic network setup and configuration for the following:

1. LANs:  Local Area Networks - PCs that are connected together within a local vicinity.
2. WANs:  larger Wide Area Networks:  groups of networks, and the Internet.  WAN topics will be covered only as far as they pertain to Internet connectivity and sharing.

PHYSICAL COMPONENTS OF A NETWORK:

Network expansion cards:

• Also called “NICs” (network interface cards)
• Network expansion cards have a cable connector which looks similar to those on modems (found on the back panel of the computer - see our network card hardware lesson if this is not familiar).  They have a single cable receptacle which is slightly larger than a phone line connector, with 8 connecting wires (rather than the 2 wires found in telephone jacks).
• Modems are a form of network expansion card:  they allow computers to connect to distant network machines via a phone line, but they are typically not used when putting machines together to form a LAN.
• Other variations of network cards include wireless network devices that use no physical cabling to transfer data, and special network cards that plug into your existing telephone lines (these cards work differently than a modem, but have a similar connector).

Network cabling:

• Cat 5:  The most common type of cabling is called “Cat 5” (category five).  Cat 5 cables have a rectangular clip end that looks like an enlarged telephone cable tip.  Cat 5 cables contain 8 wires - as opposed to the 2-4 wires found in telephone cables (only 4 are actually used).  The telephone look-alike clips on Cat 5 cabling are called “RJ-45” connectors (the technical name for telephone connectors is “RJ-11”).
• Cables may be purchased in pre-cut lengths, with the clip ends molded onto each end of the cable.  These types of cables are suitable for use when connecting small numbers of machines within close proximity to one another in a home and small office environment.  Bulk cable and Cat 5 tips may be purchased separately to satisfy longer and more specific cable length needs.  Cat 5 cable is typically sold on a spindle or in a box, in continuous lengths of 1000 feet.  The process of crimping your own Cat 5 network cable is covered further below in this lesson.
• Coaxial cable (“coax”) is another type of cable used to connect computers together on a network.  Coaxial cable is an older standard than Cat 5, but it is still in common use with cable Internet connections. The back of a cable modem is connected to the incoming coax cable provided by your cable company, and the computer is connected to that modem via its network card and a length of cat 5 wire.
• Fast fiber optic cables are used in larger networks, and although they work in much the same way as the above types, they will not be covered specifically in this lesson.

Hubs, routers, and other connectivity hardware:

• Hubs:  all of the computers on a network are plugged into a box called the “hub”.  Hubs typically contain 4-24 jacks, and can be linked together via an “uplink” port to accommodate larger systems.  Another form of hub is called a “Switch”.  Switches provide the same basic functionality as a hub, but they are slightly smarter, directing network traffic and information to the specific machines they are intended (rather than broadcasting info to the entire network).  Because switches reduce the total amount of information being sent across the network, they perform faster, and are used in situations where speed is critical, or where large amounts of data are being sent between computers.  Switches are slightly more expensive than basic hubs.
• Routers:  routers are most commonly used to share Internet connectivity.  Routers allow you to have a single broadband connection to the Internet (cable, dsl, t1, etc.) and share it between many computers.  Many of the small routers available at office supply stores and computer shops also contain a built in hub or switch - providing a single piece of hardware that connects all of your networked computers together and to the Internet.  Router configuration is covered below.
• Other components such as patch bays, rack units, and print servers will be covered in additional lessons available on our web site.

The process of physically connecting a network of computers is simple: 

• Install a network card in each computer (most new computers come with one already installed - if you don’t have one, read our hardware lessons  it’s EASY to do, and takes about 5 minutes per machine).
• Connect a cable from each computer to your hub/switch.

That’s it!  Now you need to configure the built in network software in Windows.

SETTING UP A NETWORK IN WINDOWS:

Although the main function of a computer operating system (Windows, DOS, etc.) is to provide the user with control of a machine and its components, Windows and other operating systems also provide the software necessary to connect with other computers and share resources via network hardware.  Setting up the software is really very simple, and should take less than 5 minutes per machine.  Follow the pictures and guidelines below, and you’ll be done in no time.

To access the network applet in Windows, click on START -> SETTINGS -> CONTROL PANEL -> NETWORK.  You can also access the network settings by RIGHT CLICKING  the “network neighborhood” (Windows 95/98) or “my network places” (Windows ME/XP/2000) on your desktop, and then selecting PROPERTIES.

The Network Applet has three tabs:  Configuration, Identification, and Access Control.

In order to set up a network, you will need to add 4 entries to the Configuration tab (most will already be there).  If you bought a computer with a network card already installed, most of this work will already be complete.  The entries you need are as follows:

• Client:  Client for Microsoft Networks
• Adapter:  Dial Up Adapter, and Your Particular Network Card.  The name of the network card entry will depend on the actual manufacturer of the network card installed in your machine.  The Dial Up Adapter is your modem (you won’t need to configure it).
• Protocol:  TCP/IP - if you have more than one adapter, which is the case in most machines (1 network card and 1 modem), you will have one TCP/IP entry pointing to each of those adapters. 
• Service:  File and Print Sharing for Microsoft Networks

The adapter listings are automatically added when you install your modem and network card drivers (already in the machine if you bought a computer with a modem and network card).  See our hardware lessons if you don’t have a network card or modem already installed.  If you are missing any of the other entries above, click the “ADD” button.  A list will pop up asking which type of component you want to add:  client, protocol, or service.  Select the one(s) you’re missing (you only need to do this if these components aren’t already in your configuration list):

Another menu will pop up allowing you to select the specific type of component you want - select the one(s) you’re missing:  Client for Microsoft Networks, TCP/IP, and/or File and Print Sharing for Microsoft Networks (you only need to do this if these components aren’t already in your configuration list):

Now you need to configure the TCP/IP settings.  (For many users, this will be the only required configuration step in setting up the network!).  Double-click (two quick clicks with the left mouse button) on the TCP/IP listing pointing to your network card (not the one pointing to Dial-Up Adapter).  There are several tabs on this screen. “IP Address” should be the tab selected by default (if you’re not there automatically, click on it). 

The IP address consists of four numbers, separated by dots (periods).  Each computer on your network needs to have a unique IP address (a different number in this field on each machine).  On each computer, type in a different number in this field.  The first three numbers should be 192  168  and  1 .   The last number should be a unique number for each computer.  We suggest starting with the number 11, and going up sequentially:

On Computer #1, type in:  192.168.1.11
On Computer #2, type in:  192.168.1.12
On Computer #3, type in:  192.168.1.13
On Computer #4, type in:  192.168.1.14
On Computer #5, type in:  192.168.1.15
Etc...

For all small networks, the “Subnet Mask” numbers should be set to 255.255.255.0  for every machine.

When you’ve set the IP numbers, click on OK.  This will bring you back to the main Network configuration screen. 

From there, click on the “Identification” tab.  On this screen, type in a unique name for each computer in the “Computer Name” field (ie., type in “user1” on computer #1, “user2” on computer #2, “user3” on computer #3, etc...).  In the “Workgroup” field, type in the same name on every computer.  The names in these fields can by anything you want them to be, but the Workgroup must be the same on each computer, and the Computer Name must be different on every computer.

When you have entered the TCP/IP information and the Identification information, click the OK button.  The computer will copy some files (you may be asked to insert your Windows 95/98/ME/2000/XP setup disk if the files aren’t on your computer), and then it will ask you to restart.  When the computers come back up, you will be prompted for a network login - just click OK, and your network is complete.  You will be able to see and access computers on the network by clicking on “network neighborhood” (Windows 95/98) or “my network places” (Windows ME/XP/2000) on your desktop.

SHARING RESOURCES ON NETWORKED COMPUTERS:

Now you can choose the printers, hard drives, floppies, CD-ROMS, etc.,  that you want to share.  If you have a printer attached to one machine, for example, you can print to it from any computer on the network.  If you have a CD-ROM drive on one machine, you can read from it directly from any computer on the network.  You can also open, edit, and save files and documents on any hard drive, floppy, or storage device on the system.

SHARING PRINTERS:

1.  To share a printer, go to the machine to which it is attached.  Click on START -> SETTINGS -> PRINTERS. 

2.  Right click on the name of the printer you want to share (click on it with the right mouse button), and select “Sharing”. 

3.  Select “Shared As”, and give it a name (a default name will be provided).  You can optionally assign password rights so that only specified users can have access to it.  You will see a small hand appear under the printer name once you click OK.

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4.  Next, on all of the other computers (any from which you want to be able to use the above printer), click on START -> SETTINGS -> PRINTERS -> ADD PRINTER -> (next) -> NETWORK PRINTER - >  BROWSE.  From here, you can look at all the computers on your network and find the name of the printer you shared in the last step. 

5.  Click OK, and the computer will copy some files, and add the printer to this computer’s printer list.  You need to do this on every machine on your network from which you want to print to the shared printer (ie., once you’ve shared a printer on the machine to which it is attached (steps 1-3), you need to go to every other machine on the network and add/browse for it, in order for it to be installed on each of those computers.)

Now that you’ve shared the printer, and installed it on each of the other computers, you can print to it from any machine.  In any application on any computer, click FILE -> PRINT, and select the shared printer (it will appear in your regular printer list).  The page(s) will pop out of the newly networked printer.

SHARING HARD DRIVES, CD-ROM DRIVES, AND FLOPPIES ON A NETWORK:

You can instantly copy files and documents between networked computers without having to use floppies or other transportable media.  To share any drive or folder on a computer, and make it accessible to the rest of the network, do the following:

• Double click on MY COMPUTER (on your desktop)
• Right Click on the drive you want to share (use the right mouse button), and select “Sharing” (use the left mouse button)
• Select “Shared As”, and give it a name (a default name will be provided).  You can optionally assign password rights so that only specified users can have access to it.  You can also select “read only” access so that other computers can read files on this machine, but not alter them.  You will see a small hand appear under the drive name once you click “OK”.

You can follow the same process to share only a specific folder on your hard drive (instead of the entire drive contents).  If you want to share only the contents of your “My Documents” directory, for example, right click on the My Documents folder and select “Sharing”.  

To access a shared drive or folder from any other computer on the network, click on “network neighborhood” (Windows 95/98) or “my network places” (Windows ME/XP/2000), and then on the machine containing the shared resource.   You will be able to open any of the documents on any drive/directory that has been shared. 

This is a great help when downloading and sharing files from the Internet.  It’s also essential in a work environment where files need to be accessible to all appropriate employees on different network computers.  If you need to block out some users, make sure to install the password protection features in the sharing dialogue.

MAPPING NETWORK DRIVES:

To provide quicker and more reliable access to shared drives/folders on the network, drive letters may be assigned to any shared drive or folder on the network.  If you notice that you are always clicking on your network neighborhood -> the computer named “user1” - > C drive -> My Documents, for example, you can assign that folder a drive letter which is immediately accessible on your system.  Do this:

• Right click on My Computer, select “Map Network Drive”.
• Choose a drive letter to give to that machine, and type in the location of the drive/folder you want to assign that drive letter in this format:  \\machinename\shareddrive\foldername.  If you want the computer to save this association, check the box marked “reconnect at logon”. 

If, for example, you want to call the My Documents folder on drive C of the User1 machine on your network - drive “F:” on your computer (because you access that machine, drive and folder often), click on F: in the drop down box, and type in “\\user1\c\mydocuments” as the path.  A window will pop up, showing you the contents of that folder (on that machine), and you will find a new drive letter on your computer called “F:” (C\mydocuments on user1). 

Now, whenever you want to access that remote folder from your computer, you can just click on drive F:

USING A ROUTER TO SHARE CABLE/DSL INTERNET ACCESS ON A NETWORK:

“Routers” are the easiest way to share broadband cable, dsl, and t1 Internet access.  If you have one of these types of fast Internet connections, you can share access to the Internet between every computer on your network - all you need to do is plug in a router box and entering a few settings on your computer.  Small routers for home and business come in two layouts:  with and without a built in hub/switch.  If you already have a network and a hub set up, you don’t need a router/hub combo (although this won’t hurt anything - it’ll just give you more jacks to which you can connect extra computers).  If you are setting up a new network, and you intend to install cable/dsl/t1 access, get a router/hub combo  it’ll make the job very easy.

Physical installation of the router should take less than 5 minutes.  The cables should be plugged in this order:   The cable/dsl line (coax or phone type cable coming from a wall jack) goes into the box provided by your internet service provider (called the cable/dsl modem).  The cable from that box goes into your router.  If you have a router/hub combo, just plug each of the computers directly into the combo box and you’re done.  If you have a router without a built in hub, you should plug the cable from your router into the uplink port of the hub, and all of the computers plug into the hub.  Either way, it will most likely take more time to unpack the cables then to actually set them up  : )

Configuring a home/office router is also relatively straightforward.  Most come with a “DHCP” server, which will automatically configure the network settings on each computer (once the physical connections have been made above).  In order to use the DHCP function, you’ll need to change some of the TCP/IP information in your Windows network applet (the same one described earlier in this lesson).  Click START -> SETTINGS -> CONTROL PANEL -> NETWORK (You can also access the network settings by RIGHT CLICKING  the “network neighborhood” (Windows 95/98) or “my network places” (Windows ME/XP/2000) on your desktop, and then selecting PROPERTIES).  Double click the TCP/IP listing that points to your network card (not the one pointing to your dial up adapter).  Select “Obtain IP address automatically”, and click “OK”.  Your computer will copy some files and ask you to restart.  When the computer comes back up, the router will provide it with all of the information it needs to connect to Internet.  You need to do this on every machine that you want to connect to the Internet through the router.

Next, you need to configure the router with the information provided by your Internet service provider (cable/dsl company).  You will need two pieces of information:

Your ISP’s “default gateway” IP Address (###.###.###.###)
Your ISP’s “DNS” IP Address(es) (###.###.###.###, ###.###.###.###)

If you don’t know this information, check with the documentation that came from your service provider (look for your original installation invoice)  or just give them a phone call.  They can provide it for you very quickly.

Entering the above information into your router is slightly different for every manufacturer and model, but it typically involves opening up your browser (Internet Explorer or Netscape), and typing the router address (usually 192.168.1.1), entering the default router password (try “admin”), and then filling in the default gateway and DNS #’s in the form that pops up in your browser.  Once you’ve done that, your network internet connection is complete (you may have to restart your computer(s) in order for the changes to take place).  This last step is more clearly defined in the documentation that came with your router (look for a quick start guide - it’ll show you the exact process required to enter the IP numbers obtained from your service provider).

The final step in sharing Internet access is to change your browser settings on each machine, so that it knows to look to the LAN for its Internet connection.  Click on START ->  SETTINGS -> CONTROL PANEL -> INTERNET -> CONNECTIONS -> LAN SETTINGS -> and click the box marked “Automatically Detect Settings”.  You need to do this on every computer in your network.  Once you’ve done that, you are done, and you should be able to browse freely on the Internet from every computer on your LAN.

CRIMPING YOUR OWN CAT 5 NETWORK CABLE:

The type of short molded cables available at local computer shops and office supply stores are useful for connecting PC’s to network wall jacks, and for connecting network hardware components which are physically close to one another.  If you plan to work with longer lengths of cable, or if you want to run cables between rooms in your home or business, you will need to buy a spool of cable, RJ45 tips, and a crimping tool.  Molded cables which come with ends attached by the manufacturer are less flexible in most situations.  Crimping your own network cable is a bit frustrating the first few times, but you can easily learn to do it in 5-10 minutes.  Don’t pay someone to do it for you unless you don’t mind paying high $$$ for the convenience (IT’S EASY)!

Cable is prepared for use with a crimping tool that cuts the cable at the desired length and attaches the RJ-45 tip. 

Follow the directions below to crimp Cat5 cable with an RJ-45 end:

1. Cut the cable to any length you want, then score the end of the cable sheath to expose approximately ¾ inch of the internal wires.
2. Separate the 8 internal wires.  The internal wires of a cat 5 cable are color coded orange, green, blue, and brown, and twisted together with white striped versions of the same colors.  Untwist each pair of colored and striped wires and flatten in the following order, from left to right:  white-orange, orange, white-green, blue, white-blue, green, white-brown, brown
3. Insert the wires into the RJ-45 connector in the above order.  With the RJ-45 clip facing DOWNWARDS, and the OPENING FACING YOU, lay the wires out flatly, and insert into the clip (with the colored wires lined up in the order:  wo-o-wgr-bl-wbl-gr-wbr-br, left to right).  You will see each wire slide into a separate plastic runner within the RJ-45 tip.
4. Secure the cable to the RJ45 clip by squeezing it with the specialized vise opening on the crimp tool.  This will lock the RJ-45 tip onto the end of the Cat 5 cable so that it stays attached.

Try it once, and you’ll see that it’s really not that hard to do.  The most difficult part of the process is laying out each of the 8 tiny wires in the specified order.  They have a tendency to shift around as you push them into the tip.  Be patient on your first couple attempts.  If you have trouble inserting the wires, re-cut the end of the cable and try again.  By learning to do this yourself, you’ll save hundreds of dollars in cable costs, even on a medium sized LAN setup.

Cross-Over Cables:

If you are networking 2 computers to share files and printers, you don’t even need to buy a hub.  Just create a “crossover” cable by swapping several of the Cat 5 wires, and connect the two machines directly (from network card to network card).  This is the cheapest, simplest, and fastest way to share information between two systems.  (NOTE:  If you want to add more computers to the mix later on, you will need to get a hub and use all normal straight-wired cable). 

The wiring scheme for cross over cables is virtually the same as for straight Cat 5 cable - just switch the green and orange cables so that the order is:  whitegreen  green  whiteorange  blue  whiteblue  orange  whitebrown  brown.  Plug one end of the crossover cable directly into the NIC of one machine.  Plug the other end of the crossover cable directly in the network card of the other machine, and follow all of the networking setup guidelines provided earlier in this lesson.

NETWORK TROUBLESHOOTING:

If your network computers are having trouble communicating, check the following:

• Make sure the cables are all securely connected, and that there are no breaks in the line.  You should see a “link” LED on the back of each connected computer and for each slot on the hub.  If you don’t, check the cable connections.
• If you attached the RJ45 tips to the Cat 5 cable yourself, check to make sure that they are all wired correctly.  Re-examine the color scheme above, and make sure that none of the 8 wires are in the wrong position on each cable tip.  You can buy a cable tester at most computers stores and electronics outlets that will do this for you.
• Check to make sure that all of the network components have been added to the Windows network applet (Client for Microsoft Networks, Network Adapter (your NIC card), TCP/IP Protocol, and File and Print Sharing for Microsoft Networks Service).
• Check to make sure that the IP addresses are all entered correctly on each machine (192.168.1.11, 192.168.1.12, 192.168.1.13, etc.), and that the subnet mask is 255.255.255.0
• Check to make sure that the Identification information is entered correctly on each machine (unique Computer Names on each machine, and one identical Workgroup name on all machines).
• “Ping” each of the machines on the network.  Go to START  ->  RUN ->  and type “ping 192.168.1.11”, “ping 192.168.1.12”, “ping 192.168.1.12”, etc.).  If you get a response from each IP, you can be sure that the cables are all connected properly, and that the IP information is correct.  Check Identification info again, and remove/reinstall File and Print Sharing for Microsoft networks in the network applet.
• Try logging out of Windows, and back in again, on each machine (START - > LOGOFF CURRENT USER).
• Power off and restart each computer.
• Remove and reinstall EACH of the components in the network applet (client, adapter, protocol, and service).
• If you installed your own network card, try reinstalling or replacing it.  Try temporarily removing your sound card and other expansion cards in the computer.  Also, try temporarily disabling the peripheral devices built into the motherboard  LPT, Serial, and USB ports (see our BIOS lesson).  Often, NIC cards will try to use an IRQ setting or other resource which is taken up by one of those devices.  If you are getting this type of conflict, you may need to change some of the BIOS settings (IRQ, DMA, and Memory Address settings), or the settings on your expansion cards.  Read the manual that came with your NIC card to learn how to do this for your particular piece of hardware.