Troubleshooting

IT Troubleshooting Methodology

Objective

Systematically diagnose and resolve IT issues using proven troubleshooting frameworks.

Troubleshooting Framework

1. Problem Identification

Information Gathering:

• What is the exact symptom?
• When did it start?
• What changed recently?
• Who is affected?
• Is it intermittent or constant?

Scope Definition:

• Single user vs multiple users
• Single system vs multiple systems
• Single application vs platform-wide

2. Hypothesis Generation

Common Categories:

• Configuration change
• Resource exhaustion
• Network connectivity
• Authentication/authorization
• Software bug
• Hardware failure
• External dependency

Prioritization:

• Recent changes (most likely)
• Known issues (check KB)
• Common failure modes
• Environmental factors

3. Testing and Validation

Isolation Testing:

• Can you reproduce the issue?
• Does it happen in isolation?
• What conditions trigger it?

Comparison Testing:

• Working vs non-working system
• Before vs after
• Different users/permissions

4. Resolution Implementation

Change Control:

• Document current state
• Make one change at a time
• Verify after each change
• Have rollback plan

Verification:

• Confirm issue resolved
• Check for side effects
• Test edge cases
• Get user confirmation

5. Documentation

Required Documentation:

• Root cause
• Resolution steps
• Time to resolution
• Prevention measures

Domain-Specific Checklists

Network Issues

• Check physical connectivity
• Verify IP configuration
• Test DNS resolution
• Check firewall rules
• Trace network path
• Review recent changes

Database Issues

• Check connection count
• Review slow query log
• Check disk space
• Verify replication status
• Review recent schema changes
• Check backup status

Security Issues

• Review access logs
• Check authentication systems
• Verify permissions
• Scan for vulnerabilities
• Review recent access changes
• Check compliance status

Cloud Issues

• Check service health
• Review resource limits
• Verify IAM permissions
• Check network configuration
• Review recent deployments
• Check billing/quotas