How to Troubleshoot an Internet Connection :
Losing access to your e-mail and favorite Web sites can be as frustrating as picking up a dead telephone receiver. Although the problem may lie with your ISP, it's worth knowing how to troubleshoot your own end of the line, too.
If your modem isn't getting an answer from your ISP :
1. Make sure that the cable is correctly connected to both a phone line and your modem and that, if you're using an external modem, it's connected to the PC.
2. Dial the access number for your Internet service provider (ISP) with a regular telephone and listen for a data tone. If you don't get one, then you have the wrong number or your ISP is down.
3. If your modem is internal, skip this step. Unplug the power cord from your modem and shut down your computer. Plug the modem back in and restart your computer.
4. If you have another modem cable that you can use to connect the computer to the modem, swap it with your current cable to rule out a bad cable.
If your connection is refused by your ISP :
1. Make sure your username and password are still correct. These are usually entered through a connection program that your ISP provided. You will probably have to retype your password, as you won't be able to read it on-screen.
2. Locate the TCP/IP settings for your computer. In Windows, these are found in the Network and Dial-up Connection control panels. In Mac OS 9.2 and earlier, they're in the TCP/IP control panel. In Mac OS X, they're in the Network section of System Preferences.
3. Check that the host name and domain name information are correctly entered in the TCP/IP settings. This information should have been supplied by your ISP.
If your connection is accepted but you can't load Web pages or send e-mail :
1. Call your ISP's support number to find out if you have been affected by a service outage
2. Unplug the power from your modem (whether it's telephone, DSL or cable) for at least 10 seconds, shut down your computer, plug the modem back in and restart your computer.
If your connection seems too slow :
1. Set your Windows computer to MS-DOS mode: Click on Start, Programs, MS-DOS Prompt.
2. Type "ping" followed by an Internet domain name--for example, www.google.com or www.yahoo.com. Macintosh users with OS X can use Apple's Network Utility program to "ping." Earlier versions of Mac OS don't have it built in, but freeware programs are available on the Web.
3. You should get a report saying how many milliseconds it took for your "ping" to reach the destination. A computer communicating with the Internet via a 56-KBps modem connection might typically have a 0.3-second (300-ms) or longer ping. Anything longer than 5 seconds (5,000 ms) indicates a problem with your connection that might be the fault of your ISP.
1. A telephone modem works better if it's connected directly to the phone line without anything else--a fax machine, splitter or caller-ID box--intervening.
2. Print out a paper copy of your TCP/IP settings and keep it handy as a reference to check against when you have problems.
3. It's also wise to have the phone number for your ISP's technical support printed out or stored on your computer where you can find it without having online access.