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Local Area Networks (LAN)

A LAN is basically a bunch of computers networked together in close proximity to each other. It has many uses. Over a LAN you can share files and printer access, which is very convenient for multiple computers. There are many different types of networks out there. For a small network of 4 or 5 computers, Ethernet and Fast Ethernet are sufficient. Some of the more complicated networks consist of Gigabit Ethernet, token ring, FDDI, and ATM. Ethernet is easily the simplest and cheapest option. It runs at 10 Megabits per second (Mbps), or roughly 1.2 Megabytes per second, which is more than sufficient for a small LAN.

A 10Base2, also known as Coaxial BNC, is one option to choose from. To implement this particular network, all you need is enough coaxial cable to chain all of the computers together. Each computer is connected to the cable with a simple T-connector. One end goes to the network card, the others to the incoming and outgoing cables. To create a chain, simply use a cable to connect one computer to another. The first and last computers on the chain still require T-connectors, and an additional end-piece called a 50-ohm terminator. To add another computer to the network, all you need to do is connect the computer to one end of the chain, making sure that the first and last computers have terminators attached.

Another option is the 10BaseT, also known as RJ45 twisted pair. 10BaseT is a more efficient, yet generally a more expensive solution than 10Base2. Basically, each computer on the network runs a length of cable to a central hub, which functions to pass the network traffic through each computer. Using a 10BaseT, there is no need to string every computer to another system, and removing a computer from the network is easy, since there's no chain to break.

Fast Ethernet, or 100BaseT, is the current popular standard. It has a fat 100Mbps pipe, ten times faster than the Ethernet. On 100BaseT, no single computer can fill the entire 100Mbps (10MB/s) bandwidth. Fast Ethernet only supports RJ45 Twisted Pair networks. Setting up a 100BaseT network is exactly like setting up a 10BaseT network. The only difference is that the hub and network cards have to support the 100Mbps speed. Many Fast Ethernet hubs also support Ethernet connections that allow 10Mbps network cards to communicate with 100Mbps cards. If using a RJ45/hub based network, its probably better to use Fast Ethernet over normal Ethernet because it's faster, just as easy to install, can be compatible with 10BaseT network cards, and it is only slightly more expensive. This leaves three networking options: 10Base2, 10BaseT, and 100BaseT. Fast Ethernet is probably a better option than standard Ethernet. That makes it a choice between Ethernet w/coax or Fast Ethernet. 10Base2 Ethernet is cheap and simple, but it only runs at 10Mbps, and removing or adding computers to the chain will disrupt network operations. Fast Ethernet is more complicated and more expensive, but it is ten times faster and can offer compatibility with 10Mbps network cards.

First you need to get the network interface cards. The NIC is the card that goes into each computer to make it network ready. PCI network cards are probably the best. They are generally newer and have less compatibility problems. Also, the number of ISA slots in many new systems has gone down to two, and they're usually taken up by a modem and a sound card. It is important to make sure the type of card is compatible with the type of network being used. Almost all mainstream network cards have an RJ45 connector for 10/100BaseT. An RJ45 connector looks just like a wide telephone jack. When using a 10Base2 Ethernet, cards with a BNC connector will be needed, which resembles a small, 1/3-inch long cylinder extruded from the end of card. They are often found on combo cards that have both BNC and RJ45 connectors. When using Fast Ethernet, you need 100BaseT cards, usually called 10/100BaseT because they're backwards compatible with 10BaseT networks.

Setting up a 10Base2 network is not very complicated. You will need a length of cable between each computer on the network, and one T-connector for each system. The T-connector is a 3-way adapter which plugs into the BNC connector on the network card. This leaves two connections free for cabling from other computer systems on the network. The last computer on either end of the network requires a 50-Ohm terminator. At each end of the network chain, the cable goes into one end of the T-connector, and a 50 Ohm terminator attaches to the other end, informing the system that the network ends there. One of the drawbacks of a 10Base2 system is adding and removing systems from the network. Adding a system requires breaking the chain, which will disrupt traffic from any other computer on the network. Removing a system can also break the chain, but this can be fixed by by taking off the T-connector without removing the cable,or terminator, from each end.
When using a 10BaseT or 100BaseT, you will need a hub. The speed of the hub determines the speed of the network. Hubs come in three types: 10BaseT, 100BaseT, or 10/100BaseT autosensing. 10BaseT hubs are for 10Mbps networks, and are the cheapest ones out there. They are only compatible with 10BaseT or 10/100BaseT cards. 100BaseT hubs are for 100Mbps networks, and they are only compatible with 100BaseT or 10/100BaseT cards. 10/100 autosensing hubs are compatible with 10BaseT, 100BaseT, and 10/100BaseT network cards. 10BaseT cards are able to connect to 10/100 networks, but they only transfer and receive at 10Mbps.

Once you choose the type of hub, you will need to decide on the number of ports. The smallest hubs come with 4,5, or 8 ports. There are much larger hubs out there, depending on the size of your LAN. You need one port for each computer on the network. It is good to have extra ports to leave room for expansion. Most hubs are also able to chain to other hubs to make a larger network.
Once you've got the hub and power supply connected, all that's left is to connect the cabling. 10/100BaseT networks require cabling with RJ45 jacks, often referred to as Cat5 cable. One end of the Cat5 goes into the network card, and the other end plugs into a free port on the hub. There's no need for T-connectors or terminators, and since each computer connection is independent of another, removing a system from the network won't interfere with other network operations. All that's left is to power up the system, Windows Plug and Play will do most of the work, and configure the IPX and TCP/IP protocols.

Installing the network card in Windows will probably be the most difficult part of setting up a LAN. The quality of a NIC card, and the number of legacy cards in your system will determine how easy the installation will be, and how many problems you'll run into afterwards. I am assuming running Win95 or 98 because they react the same to any kind of NIC installation routine.

After physically inserting the card into the system, boot up the computer. Hopefully, Windows will detect the new hardware and launch the Add New Hardware Wizard. At this point, Windows will either ask for the Win98 CD or more commonly, ask for a driver disk from the manufacturer. When Windows asks if you have the driver files, insert the NIC installation disk into your floppy drive.
If Windows does not detect your new hardware, the card may be seated improperly, or you may not have a Plug'n'Play card. If you have a PCI NIC or know the card is plug and play, switching slots may need to be done. Many motherboards tend to assign different IRQ addresses to different slots, and if one of the PCI slots is designated as a save slot, your system may not recognize the card. If an ISA network card isn't Plug'n'Play, you will probably have to run a setup program from disk manually. The NIC installation disk might also include a DOS setup utility that will allow you to test and configure your card. Once the installation is complete, Windows will ask to restart your system.
After rebooting your system, check the Device Manager in the System window of the Control Panel. Make sure there is not a yellow exclamation symbol next to your network card. If there is a symbol, there's probably a resource conflict between the NIC and another system component. Older cards tend to eat up valuable resource settings, and reduce the possible number of configuration options for your NIC. Try changing the resource settings of the NIC. Double click the device and check the Device Status box in the General tab. Any system resource conflicts will be listed here. If you are experiencing a problem, click on the Resources tab and view the Conflicting device list. You should then be able to select the "Set Configuration Manually" button and choose a new I/O range or IRQ to free the conflict. Once done, you'll need to reboot. Then, go back to Device Manager and confirm that the network card is recognized properly. Once Windows recognizes your NIC without any resource conflicts, you're ready to start selecting protocols.

After everything is installed you'll need to setup the windows 95/98 peer to peer networking. Go into the Control Panel and select the "Network Icon. This will bring up your network properties screen. Your network card should appear in the list of installed network components. If it's not there, the network card isn't installed properly. Check to see if Windows already installed TCP/IP and IPX/SPX for the network card. If they're not there, you'll have to install it yourself. You just need your Windows 95/98 install CD, or have the installation files somewhere on your hard disk. This is how you install TCP/IP first. Go to the network menu and highlight your network card. Now, click on the add button. That will take you to the "Select Network Component Type" window. Highlight protocol, then click add. That will open the "Select Network Protocol" window. Go down the left side, and select "Microsoft" from the list of manufacturers on the left. Then select "TCP/IP" from the list of Network Protocols on the right. Click OK. That will return you to the Network window. Now if you repeat the above steps, but choose "IPX/SPX-compatible Protocol" instead of "TCP/IP" in the "Select Network Protocol" window, you should have a new "IPX/SPX-compatible Protocol" line in the list of installed components. Lastly, repeat the above steps again, but choose "NetBEUI" in the "Select Network Protocol" window. NetBEUI will make Microsoft file and printer sharing much better. After installing NetBEUI, go to its properties window, and check the " Set this protocol to be the default protocol" in the advanced tab. Only install NetBEUI if you aren't going to use Microsoft file and printer sharing. One of the things you'll commonly see with a new network is the default protocol NetBIOS, which allows for network-specific programs to run across IPX.

After installing TCP/IP and IPX/SPX, we need to assign the IP address and subnet mask. Each computer on the network must have a unique network address. Highlight the "TCP/IP" line in the list of installed components. Now click on properties. That will open up the TCP/IP Properties window. Select "Specify an IP address." According to RFC 1918, private IP addresses should stay within these ranges:

10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255

If none of the computers on the LAN have access to the Internet, you can use any address. However, it is considered good practice to stay within the internal-networking range above. For the subnet mask, use the popular 255.255.255.0 for all the computers. A good way is assigning the first computer 10.0.0.1, the second 10.0.0.2, the third 10.0.0.4, and so on. You can also choose 192.168.0.1, 192.168.0.2, etc. Leave WINS, Gateway, and DNS disabled. These settings exist to facilitate connections to the Internet and/or large networks. You won't be needing them for a small LAN. However, chances are at least one of the computers in your network will have access to the Internet. That computer is going to require a "real" IP, one approved for Internet use and assigned by your ISP. In this case, it's useful to have IPX/SPX configured correctly for Windows Networking, so the other computers on the network will still be able tocommunicate properly. You'll also need to install Microsoft Networking so the systems participating on the LAN can communicate through the TCP/IP and IPX protocols. Access

Network Properties, select "Add," "Client." Select "Microsoft," and "Client for Microsoft Networks."
If you want to be able to share resources with the other computers on the net such as trading files and programs or sharing printers, you'll need to enable Microsoft File and Print Sharing. Click the add button in the Network window. Select service at the bottom of the list. Click add. That will open the "Select Network Service" window. Select "Microsoft" on the left, and then select "File and Printer Sharing for Microsoft Networks" on the right. Click OK. There should be a new "File and printer sharing for Microsoft Networks" line at the bottom of the installed network components list. Now you want to go back and verify that everything is set up correctly. Pull up TCP/IP and select the Bindings tab. Verify that both "File and Print Sharing" and "Client for Microsoft Networks" are checked, and do the same for IPX/SPX. You must share something like a printer, drive, folder, or anything else on the system for it to appear in the network neighborhood of other computers on the network. You can do this by right-clicking on the drive to be shared, and select "sharing..." Select a share name, hit "apply" and your drive or printer will appear on the network. You'll probably have to reboot again, at which point you'll see the "Network Neighborhood" icon displayed on your desktop. When you double-click Network Neighborhood, you should see at least two icons - "Entire Network" and your own computer as named in the "Identification" tab of Network properties.

Your computer's name does not necessarily match the name you've given for your system's "My Computer" icon. Follow the same directions for each of the other computers you wish to connect to the LAN, and they should begin to appear on the network. Windows should broadcast its presence to other systems on the network. It may take up to 15 minutes or more for a system to be initially polled and recognized. A reboot may speed things up, but if each system can see itself in Network Neighborhood, hit View | Refresh a few times. If everything is set up correctly, you'll see each system listed in the Network Neighborhood. From here you should be able to set up shared directories on your hard drive to easily exchange files.

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