Network Troubleshooting Methodology

Identify the problem

• Gather information

• Question users

• Identify symptoms

• Determine if anything has changed

• Duplicate the problem, if possible - Approach multiple problems individually

Establish a theory of probable cause

• Question the obvious

• Consider multiple approaches

• Top-to-bottom/bottom-to-top OSI model

• Divide and conquer

Test the theory to determine the cause

• If the theory is confirmed, determine the next steps to resolve the problem

• If the theory is not confirmed, reestablish a new theory or escalate

Establish a plan of action to resolve the problem and identify potential effects

• Plan before doing anything.

• Change management process may be required.

• Determine how many steps are needed for the plan of action.

Implement the solution or escalate as necessary

• When should the solution be implemented.

• Ensure there is a backout plan to ensure you can roll-back the change.

Verify full system functionality and, if applicable, implement preventive measures

• Continuous monitoring of the system and network.

• Use a baseline to compare whether the system or network is working at an acceptable level.

• Observe system logs for any errors.

Document findings, actions, outcomes, and lessons learned

• The documentation is helpful such that if the issues reoccurs in the future.

• Steps taken and their outcomes.