Use Basic Diagnostics

Network connectivity can be notoriously difficult to maintain and troubleshoot when it fails. After you check the physical connection and ensure all of the correct drivers are in place, you begin looking for other potential sources of the problem. The command line provides access to a number of diagnostic aids that can make troubleshooting easier. The following sections provide an overview of the most important troubleshooting aids.

Check Connections

The Packet Internet Groper (PING) utility makes it possible to check connectivity to a specific resource. For example, if you want to check the connection to a machine on the network named WinServer, you’d type PING WinServer and press Enter. When everything is working correctly, you see four tests of the connection as shown in Figure 9-3. The output shows the IP address of the remote connection, the amount of data sent to it, and how long the connection took to complete. At the end of the test you see statistics, such as the number of tests run and how many times the test failed. PING even provides times so that you can use it to detect slow connections.