CompTIA Troubleshooting Methodology & Flowcharts

CompTIA tests process, not guesswork. Both the A+ and Network+ exams expect you to follow a structured troubleshooting methodology. Memorize the order of these steps — exam questions frequently ask "what should you do next?"

The 6-step methodology (A+ & Network+)

  1. 1

    Identify the problem

    Gather information from the user, identify symptoms, question the obvious, and determine if anything changed. Back up before making changes.

  2. 2

    Establish a theory of probable cause

    Question the obvious first. Consider multiple causes (the OSI model bottom-to-top or top-to-bottom helps for network issues).

  3. 3

    Test the theory to determine cause

    If the theory is confirmed, move on. If not, establish a new theory or escalate.

  4. 4

    Establish a plan of action

    Create a plan to resolve the problem and identify potential side effects.

  5. 5

    Implement the solution

    Apply the fix — or escalate if it is beyond your scope/authority.

  6. 6

    Verify full system functionality

    Confirm the fix works and, if applicable, implement preventive measures.

  7. 7

    Document findings

    Record the actions, outcomes, and lessons learned for future reference.

Exam tip

Remember to back up before making changes and to escalate when a problem is outside your authority. "Question the obvious" is part of establishing a theory — not a separate first step.

Network troubleshooting with the OSI model

For connectivity issues, work the OSI model methodically — either bottom-up (check the cable/link first) or top-down (start with the application). Verify physical connectivity, then IP configuration (ipconfig/ip addr), then reachability (ping, traceroute), then name resolution (nslookup).

Put the method into practice with A+ Core 2 practice questions and Network+ practice questions.