Chapters

Introduction Planning Local Area Network Broadband Sharing Troubleshooting Common Problems

Network Trouble-shooting

Testing Ethernet Adapter LAN Functionality Testing Internet Connectivity Slow or Overloaded Network Network Troubleshooting Tools

Useful Tools for Network Troubleshooting

In this section, I'd like to list the tools mentioned previously, and add a few others that I use. At some point, I plan to expand this section with examples for the tools not already used elsewhere. For now, this is just a list of those tools with a short explanation of each. It's a work in progress.

ipconfig - The command used in a command prompt window on Windows-based systems to display the current IP settings of the Ethernet adapters.

netstat - A command used in a command prompt window that will return various sorts of network status and configuration information. It can be used to find out how your computer is routing data and what ports are listening for connections or using outgoing connections.

nslookup - A command used in a command prompt window that queries a domain name server (DNS) with a command network name (e.g., www.google.com) and returns an IP address associated with that name.

ping - The command used in a command or Telnet window that can be used to send a test message to another device which will reply with the same message.

Ping Plotter - A Windows program available in free and profession versions that does the same thing as tracert, but with a graphical display that makes it easy to see where network slowdowns are occurring.

Speed tests - Web sites that will allow you to perform a speed test over the Internet to see if you are getting the speed you are paying for. A good speed test can be found at www.broadbandreports.com.

tracert - A command used in a command prompt window on Windows-based systems to trace the route taken by a packet send from your computer to another computer or device. The IP addresses of the intermediate nodes are given along with the time it took for the response. The information is the same as that returned by Ping Plotter, but is included with the Windows OS like ipconfig, ping, nslookup, and netstat.

What's Running - A Windows program that can ferret out what services are running including one buried inside svchost processes. Unfortunately, it hasn't been updated in some time. The current version (2.2) doesn't play well with Windows Vista. Windows Vista's Task Manager has a Services tab that provides some of the functions that What's Running does, but not at as fine of level of granuarity.

WinIPconfig - A Windows GUI version of the ipconfig command.

Wireshark - (Formerly known as Ethereal) A program for Windows, OS X & Linux that can be configured to capture data traffic based on a set of criteria like source IP address, port number used, etc. Gathers statistics on what it captures.