Addressing Network Connectivity Problems
BackBy Andrew Bonslater — December 2008
Q: I’m running into connectivity issues. Can you offer advice on how to diagnose a connection issue and name a tool or application that can help?
A: Troubleshooting connectivity issues can be, well, troublesome. Always have a plan of action, or you can easily make problems worse. The following action plan is a good place to start:
1. Data link: Check cables, the network adapter and lights.
2. Software: Monitor the firewall and any other applications.
3. Network: Verify IP configuration and network connection.
As you complete each step, check to see if your network connection has started working.
Start with the data link by checking some of the obvious components of your network. This may sound simple, but sometimes ignoring the most obvious things can waste a lot of time. Make sure your network cable is properly plugged into your network adapter slot on your computer and the other end of the cable is properly connected to your router or modem, depending on your network setup.
If you are using a modem, usually there are lights that detect a connection with your computer and indicate whether the modem is responding. Try unplugging your model and leaving it unplugged for about five to 10 minutes. Plug it back in and give it some time to load. If your modem is connected to a router, perform the same steps for the router as you did with the modem. Lastly, check the lights on your network adapter on your computer. Typically there is a still green light and a flashing orange light that indicate whether a good connection has been detected.
Next, check the software on your computer to see if there are any programs interrupting your network access. If you have a software firewall running on your computer, try disabling it temporarily. Also, remember that Windows XP and Vista have a built-in firewall that can be enabled or disabled from the Control Panel. If disabling the firewall fixes your connection problem, then you will want to check the configuration of your firewall. It’s important to keep your firewall running to prevent vulnerability to network attacks and viruses. If you have any software applications running on your computer, close them all out and try restarting your computer.
Make sure your network connection is enabled by opening the Network Connections application in the Control Panel. In Network Connections, you should see Local Area Connection. Right click on the Local Area Connection and click on Status. If you are connected, the status window should say “Connected.” If not, click on the Support tab and click the Repair button.
If the repair fails, or does not do anything, open the command prompt by going to Start, then Run, then type “cmd” and click the OK button. When the command prompt displays, type “ipconfig” without the quotation marks in the command window. This command will display your IP configuration settings. Now type “ipconfig /release”. When your IP configuration has been released, type “ipconfig /renew”. This will renew your IP configuration.
Now check your connection to see if it’s working. You can run the ping command from the command window to see if you are able to ping a Web site such as Google. To ping Google, the full command is “ping www.google.com”.
These simple steps should give you a good start for troubleshooting network connectivity issues. If you continue to experience problems, you may want to contact your Internet service provider to find out whether the problems are external.
Andrew Bonslater, MCTS, MCSD, MCAD, is a senior staff member with Crowe Horwath LLP in the Chicago office. He can be reached at firstname.lastname@example.org.