Have you ever needed to operate a PC when you're not sitting in front of that particular computer? You can, using free software called VNC (Virtual Network Computing). Once you install the VNC server on a computer, you can control it from any other computer on the LAN. If you have a full-time Internet connection, you can even access that PC from any other computer on the Internet. You can use VNC to adjust the computer in the den from your office or to retrieve an important file from your home computer when you're out of town. The two computers don't even need to run the same operating system: You can access your Windows PC from a Mac, Linux PC, or even a PDA. Download the free software from www.realvnc.com/dowload.html.
One of the best reasons for setting up a LAN is to play games. Many popular games, such as Quake III and Half-Life, include network modes that let you play competitively or cooperatively with friends. If you have an Ethernet hub or switch, you can invite friends (and their PCs) over for a “LAN party.” For gaming, a switch is preferable to a hub; they do the same basic job, but a switch uses the network's resources more efficiently. Just don't invite more friends than you have ports on the switch, or someone will be left playing Solitaire. Use straight through cables to connect each PC to the switch and then check the game's documentation for details on running a networked game.
Every device on a network, whether the Internet or a LAN, has an IP (Internet Protocol) address. An IP address is four numbers separated by periods, such as 192.168.1.101. Only one computer can use a particular IP address at any time. If more than one machine attempts to access the network using the same address, neither one will be able to access the network. Windows will show a warning message if this happens, but you'll have to change the IP address of one or both PCs. To do so in WinXP, go to Control Panel, click Network And Internet Connections, then Network Connections. Double-click the icon for your LAN connection, click Properties, then, under the Networking tab, double-click Internet Protocol (TCP/IP). (In Win98, it's Control Panel, Networking, TCP/IP.) In the Use The Following IP Address pane, change the address. If the router on your LAN includes a DHCP (Dynamic Host Configuration Protocol) server, it is better to choose Obtain An IP Address Automatically. The router will assign an address to each PC, assuring there are no duplicates.
The amount of data that your network can send and receive in a given period of time is known as bandwidth. Your modem, for instance, might be able to download at 56Kbps (kilobits per second)—that's a measurement of its bandwidth. Although people often say that a broadband connection (like a cable or DSL [Digital Subscriber Line] modem) is “faster” than a modem, it is more accurate to say that the broadband connection has higher bandwidth. You can measure the bandwidth of your Internet connection: Point your Web browser to www.pcpitstop.com/internet. The tools there will provide a snapshot of your connection's upload and download speeds. For a longer-term graph of your bandwidth use, download Ativa Pro Net Meter (free; www.ativapro.com/download.htm), which will show your bandwidth usage as you use the Internet and your LAN.
Latency is the speed of an Internet or LAN connection, measured by the time it takes data to arrive at its destination. To understand the difference between bandwidth and latency, consider taking a trip across town. A Porsche can get you there quickly but can't move many people at once: It has low latency and low bandwidth. A bus can get a lot of people to the destination but is relatively slow: It has high bandwidth and high latency. You can measure the latency of your Internet or LAN connection using PING (Packet Internet Groper), a command-line tool that is built into Windows. To access it, open the Start menu, choose Run, then type COMMAND and click OK. Now type ping yahoo.com. The PC will send several test packets to Yahoo!'s Web server, each time waiting for a reply. When it is done, you'll see the minimum, maximum, and average times it took for the test packets to make the round trip, measured in milliseconds. Consistently high PING times to various servers (more than 300 milliseconds) may indicate a problem with your Internet connection.
PING is a great network diagnostic tool. If you're having trouble accessing other computers on your LAN or the Internet, try typing PING 127.0.0.1 in the Run dialog box. This asks the PC to send PING packets to itself. If they don't get through, something is wrong with the network configuration or Ethernet drivers on that PC. If the PC can ping itself, try pinging your network router next (the IP address may be 192.168.1.1, but this varies from network to network). If you can't ping the router, there's probably something wrong with the router or the cable that connects it to the PC. Finally, try pinging several Web sites. If you can't reach them, either your Internet connection or the connection between your router and the modem is down.
If you often find yourself retrieving files from, or saving files to, a particular computer on your LAN, you can use the Map Network Drive command to save time. The function, available in WinXP and Win98, makes a networked computer act just like a drive connected directly to your PC. Begin by viewing a networked computer in Windows Explorer or My Network Places. From the Tools menu, choose Map Network Drive. Choose a drive letter to represent that networked drive and then press the Browse button to choose the computer and folder to associate with that drive letter. Click Reconnect At Startup to make that drive accessible automatically every time you boot the PC. Select Finish. From now on, that remote computer will look just like another drive on your PC in Open and Save dialog boxes, Windows Explorer, and elsewhere.
Have you ever suffered with an especially slow Internet connection and wondered who is to blame? The problem could have many causes, ranging from your ISP to your LAN connection to the Internet as a whole. You can use an Internet monitoring site to find out. Internet Traffic Report (www.internettrafficreport.com) shows, at a glance, how reliable and speedy the 'Net is today. You'll see a map of the world, with a number representing each continent the site covers. High numbers mean that connections to that continent have been generally fast and reliable in the past few minutes.
Reprinted with permission from PC Today magazine.