Set up a wireless network using a router

IP ADDRESS AGONY

Your computer is a fountain of useful information, a treasure trove of music and video that wants nothing more than to share its wealth with the world. But, alas, a peculiar affliction seems to have rendered it unable to converse with its own kind. You just finished connecting it and two other computers in your home to your wireless router, but when you explore your machine's network neighborhood, you find only endless white blank space.

Are these computers destined to live in the darkness of their private worlds? Why can't they see each other?

These tips can help you use your wireless router to share your Internet connection.

1. Check your computers' IP addresses.
First, confirm that all of your computers have matching, compatible IP addresses. To do this on a Windows PC, open a command prompt by clicking Start > Run. Type cmd into the text field and click OK. After the command-prompt window opens, type ipconfig and hit Enter. A new command prompt appears and above it, a list that includes the IP address and subnet mask for your computer's network adapter. The computers on your network use each other's IP addresses to send and receive data packets. If your networks' addresses are invalid, sent data will have nowhere to go and will ultimately be discarded. The IP addresses of your computer should all be unique, but typically will all start with the same initial nine digits. For example, if your router's address is 192.168.1.1, then the addresses of two of the computers on your network might be 192.168.1.20 and 192.168.1.30.

You should also make sure that all of your computers have the same subnet mask. A subnet mask is used to divide your IP address into two separate addresses: a network address and a node, or individual computer, address. For example, if your subnet mask is 255.255.255.0 and your IP address is 192.168.1.12, then the first three sets of digits, 192.168.1, are your network address, and all of the computers on your network will need IP addresses with these same first three sets of digits. In this case, 12 is the individual computer address on your network, and it shouldn't be repeated for any of the computers on your network.


2. Set up Windows XP file sharing.
Before you set up file sharing, make sure that all of your computers are assigned to the same Windows workgroup. A Windows workgroup is a group of PCs running Windows that are configured to share files and printers. Right-click the My Computer icon on your desktop and select Properties. The PC's workgroup name is listed on the Computer Name tab of the System Properties window. There's also a button on this tab that lets you change the workgroup name. If necessary, change the workgroup assignments on your computers so that they match.
You can set up file sharing on PCs running Windows XP by right-clicking the folder you want to share, then selecting "Sharing and security." On the Sharing tab, check the box marked "Share this folder on the network." You can also enter a share name for the folder, which is the name the folder will have when it is accessed remotely from other computers. For example, you can share a folder on your computer called My Images and give it a share name of Jill's Images, making it less confusing for those accessing the folder from other computers. You can also choose to let others change files in your shared folder from other computers by checking the box marked "Allow network users to change my files." If you leave this box unchecked, users on other computers will be able to read your files, but they won't be able to change them. When you search the network neighborhood from other computers, you should now see the shared folder.

Note: Allowing file sharing between your Windows PCs creates a new point of entry into the computers on your network. While the risk is nothing to lose sleep over, it is a good idea to use it sparingly. If you're not planning to share files, disable it. If you are planning to share files, limit the number of folders you share. Generally, it is not a good idea to share your entire hard drive.

Sharing an internet connection using a router

One dark and stormy evening, you decide to share your Internet connection with the rest of your household. So you bring home a wireless router, an innocent-looking little gadget with a pair of black antennas sticking out of the back that give it the look of a squat, electronic bunny. When you connect it to your broadband modem and power it on, blinking lights on the front of the unit begin to contort themselves into an evil grimace. Suddenly overcome with fear, you check your computers to see if your wireless connection is working. You're somewhat relieved to see an icon in the lower-right side of the screen telling you that your wireless connection is working.

With great trepidation, you open a browser to surf the Internet, and that's when terror strikes. Your home page cannot be found. You try Google, Yahoo, and CNET, and to your dismay, they are gone, all gone. The World Wide Web has vanished, and each time you try to access a different site, your router's evil blinking grimace shines on.

These tips can help you use your wireless router to share your Internet connection.

1. Configure your router for PPPoE.
In many cases, a wireless router willlet you share your Internet connection without much fiddling on your part. However, some Internet service providers use technologies that make Internet sharing more difficult. Many DSL providers use PPPoE, or point-to-point protocol over Ethernet, as a means of permitting their customers to log on to their broadband service. In order to establish your Internet connection, you must first submit a username and password via PPPoE, a process called authentication. Often, this authentication is handled by software that you or your service provider installed on one of your computers when you purchased the service. You can't install the same software on your router, but you can configure your router to supply the right PPPoE information for your service. You should have this information in the documentation you received when you purchased the service, but you can also call your provider to get it. Simply enter the information in the PPPoE section of your router's browser-based configuration tool and reboot your router; now the router will handle your PPPoE authentication and provide broadband Internet access to all of the devices connecting through it.

2. Give your router your DNS information.
If you're still unable to call up Web pages, make sure that you've entered the correct IP addresses for your service provider's domain name servers along with your PPPoE login information. Domain name servers take easy-to-remember URLs, such as www.cnet.com, and map them to their routable IP addresses. Ultimately, it's the IP address that lets you locate the computer with the Web page you're looking for on the Internet. Without a domain name server, or DNS, URLs are useless. Most service providers give you two DNS addresses: a primary address and a secondary one. The secondary server is a backup should the primary DNS server fail. If your router lacks correct addresses for your service's DNS servers, it may be able to connect you to the Internet, but it won't be able to help you use URLs to call up Web pages. Here, too, your service provider should have sent you the IP addresses of your primary and secondary DNS servers when you purchased broadband service. If it didn't or if you misplaced the information, call your service provider and ask for the IP addresses of your DNS servers.