- Understand how resilience supports availability
- Explain redundancy, backups, and recovery planning
- Know common recovery terms such as RTO and RPO
- Cyber Resilience
- Redundancy
- Backups
- Recovery Terms
- Site Types
- Business Continuity and Disaster Recovery
- Testing and Validation
- Key Takeaways
- Cyber Resilience: The ability to continue operating, respond to disruption, recover services, and improve after an incident.
- Resilience is closely connected to availability in the CIA triad.
- The goal is to reduce downtime and keep critical business services running.
- Redundancy: Duplicate systems, components, or paths used to avoid a single point of failure.
Examples:
- Multiple power supplies
- UPS and generator
- RAID storage
- Load balancer
- Failover server
- Multiple network links
- Secondary DNS
- Replicated database
- Cloud availability zones
- Backup: A copy of data that can be restored after deletion, corruption, ransomware, hardware failure, or disaster.
Backup best practices:
- Encrypt backups
- Protect backup credentials
- Monitor backup jobs
- Test restoration
- Keep offline or immutable copies where possible
- Store backups separately from production systems
Backup types:
- Full Backup: Copies all selected data.
- Incremental Backup: Copies changes since the last backup.
- Differential Backup: Copies changes since the last full backup.
- RTO: Recovery Time Objective; how quickly a service must be restored.
- RPO: Recovery Point Objective; how much data loss is acceptable.
- MTD: Maximum Tolerable Downtime; longest acceptable outage.
- MTTR: Mean Time To Repair.
- MTBF: Mean Time Between Failures.
- Hot Site: Fully ready recovery site with systems and data available quickly.
- Warm Site: Partially ready site that needs some setup.
- Cold Site: Basic facility with little or no active equipment.
- Business Continuity: Keeps essential business functions operating during disruption.
- Disaster Recovery: Restores technology systems after disruption.
Example:
- Business continuity may define how payroll continues.
- Disaster recovery may define how payroll servers are restored.
- Plans must be tested before a real incident.
- Backup restore tests confirm that recovery is actually possible.
- Tabletop exercises help teams practice decisions and communication.
- Redundancy helps prevent downtime.
- Backups help recover after failure or compromise.
- Recovery plans must be tested, not only documented.