1.3.3 Documentation & Version Control

Documentation + Version Control keep change management organized, secure, and audit-ready.

Updating diagrams

• Network / architecture / system diagrams = living documents
• Update immediately after:
• Adding a firewall
• Moving a server to cloud
• Creating a new subnet
• Deploying IDS / IPS
• Outdated diagram → wrong decisions during troubleshooting and IR

Updating policies & procedures

• Policy → the rules
• Procedure → the steps to follow the rules
• Example: switch to MFA → must also update policies + procedures, not just tech
• Required for audits / ISO 27001 / NIST compliance

Version Control

• Keeps full history of every change → no overwriting
• Enables rollback (v1.2 broke prod → roll back to v1.1)
• Tracks metadata → author, date, time, reason → audit trail
• Enables multi-person collaboration without losing history
• Helps identify exactly when a vulnerability was introduced

Exam takeaway

Every change → - Diagrams reflect reality - Policies & procedures reflect current rules - Version Control tracks who/when/what + enables rollback