2. Introduction to Computer Networks Introduction to Computer Networks

3. Troubleshooting a Network This lesson surveys the basics of network troubleshooting and teaches strategies for how to isolate, identify, prioritize, and resolve problems.

4. Understanding the Problem The process of troubleshooting a computer network problem can be divided into five steps.The process of troubleshooting a computer network problem can be divided into five steps. Step 1: Defining the ProblemStep 1: Defining the Problem Step 2: Isolating the CauseStep 2: Isolating the Cause Step 3: Planning the RepairStep 3: Planning the Repair Step 4: Confirming the ResultsStep 4: Confirming the Results Step 5: Documenting the OutcomeStep 5: Documenting the Outcome

5. Segmenting the Problem If the initial review of network statistics and symptoms does not expose an obvious problem, dividing the network into smaller parts to isolate the cause is the next step in the troubleshooting process.If the initial review of network statistics and symptoms does not expose an obvious problem, dividing the network into smaller parts to isolate the cause is the next step in the troubleshooting process. The first question to ask is whether the problem stems from the hardware, or the software.The first question to ask is whether the problem stems from the hardware, or the software. If the problem appears to be hardware-based, start by looking at only one segment of the network, then looking at only one type of hardware.If the problem appears to be hardware-based, start by looking at only one segment of the network, then looking at only one type of hardware.

6. Isolating the Problem After you have gathered the information, rank the list of possible causes in order, beginning with the most likely and moving to the least likely cause of the problem.After you have gathered the information, rank the list of possible causes in order, beginning with the most likely and moving to the least likely cause of the problem. Then select the most likely candidate from the list of possible causes, test it and see if that is the problem. Then select the most likely candidate from the list of possible causes, test it and see if that is the problem. Start from the most obvious and work to the most difficult. Start from the most obvious and work to the most difficult.

7. Setting Priorities A fundamental element in network problem solving is setting priorities.A fundamental element in network problem solving is setting priorities. While the simplest approach is to prioritize on a "first come, first served" basis, this does not always work, as some failures are more critical to resolve than others.While the simplest approach is to prioritize on a "first come, first served" basis, this does not always work, as some failures are more critical to resolve than others. Therefore, the initial step is to assess the problem's impact on the ability to maintain operations.Therefore, the initial step is to assess the problem's impact on the ability to maintain operations.

8. Summary (1) It is essential to take a structured approach to troubleshooting in order to resolve network problems.It is essential to take a structured approach to troubleshooting in order to resolve network problems. Collecting information lays the foundation for isolating a problem.Collecting information lays the foundation for isolating a problem. Asking users the right questions will provide the most information. Use open-ended questions.Asking users the right questions will provide the most information. Use open-ended questions. The troubleshooting process includes five steps: defining the problem, isolating the cause, making the repair, confirming the solution, and documenting the outcome.The troubleshooting process includes five steps: defining the problem, isolating the cause, making the repair, confirming the solution, and documenting the outcome.

9. Summary (2) If the cause of a problem is not obvious, divide the network into logical groups such as clients, NICs, hubs, cabling and connectors, servers, connectivity components, and protocols, and check each separately.If the cause of a problem is not obvious, divide the network into logical groups such as clients, NICs, hubs, cabling and connectors, servers, connectivity components, and protocols, and check each separately. Repairing network problems sometimes requires working on several problems at once. Because it is not possible to repair everything at the same time, you will need to establish priorities.Repairing network problems sometimes requires working on several problems at once. Because it is not possible to repair everything at the same time, you will need to establish priorities. The network administrator should establish the priorities that affect the integrity of the network.The network administrator should establish the priorities that affect the integrity of the network.