Windows XP and Windows 2000 contain several basic troubleshooting tools. In addition to these built-in software utilities, I stock my toolbox with a cable scanner, a volt/ohm meter, and a tone generator.

Pathping
Pathping lets you verify that you can contact a host. From a command line, type

pathping

The results give you some basic information about packet loss.

Ipconfig
Use Ipconfig to display a workstation's IP configuration. From a command line, type

ipconfig /all

You can study the results to determine the following:

  • Verify that the workstation has a correct IP address and subnet mask. An incorrect IP address or subnet mask can cause connectivity problems.
  • If DHCP is enabled, verify that the workstation has leased an IP address. If you can't obtain an IP address, you might have a problem with the DHCP server.
  • Verify the default gateway. An incorrect default gateway can cause connectivity problems with remote networks or the Internet.
  • Verify the DNS server. XP and Win2K rely on DNS for name resolution. Generally, a workstation should point to a Win2K server for DNS.

Nslookup
Use Name Server Lookup (Nslookup) to check DNS entries on a DNS server. From a command line, type

nslookup

I use NSLookup to verify mail exchange (MX) records when troubleshooting Internet email delivery problems.

Route Print
The Route Print command displays the learned and static routes on the local machine. This utility is useful in conjunction with the Ping, Tracert, and Pathping commands to help you determine the route that packets are traveling. From a command line, type

route print

You can also use Route Add to enter static routes on servers and workstations.

Netdiag
The Netdiag command returns useful information about a machine's network configuration, including IP configuration, server name, default gateway test, Winsock test, DNS test, and lookback test. For the best results, make sure to bind TCP/IP to one of the network adapters on the server. The output from this utility is in netdiag.log.