Troubleshooting Overview

When troubleshooting any problem, ask yourself the following questions:

  • What application is failing? What works? What doesn't work?

  • Is the problem basic IP connectivity or is it name resolution? If the problem is name resolution, does the failing application use NetBIOS names or DNS names and host names?

  • How are the things that do and don't work related?

  • Have the things that don't work ever worked on this computer or network?

  • If so, what has changed since they last worked?

Ideally, a review of the location and timing of the problem helps narrow the problem's scope. In addition, you can examine TCP/IP failures systematically by referring to the steps needed for successful computer communications . These steps are described in the following sections; suggested methods for troubleshooting begin in the "Unable to Resolve a Host or NetBIOS Name" section of this chapter.