The ultimate how to implement guide to ISO 27001 Annex A 5.30 ICT Readiness for Business Continuity.
Table of contents
- 1. Align ICT Recovery Objectives with BIA
- 2. Implement High Availability (HA) at the Component Level
- 3. Verify Network Path Diversity
- 4. Configure Automated Backup Replication
- 5. Provision Standby Capacity
- 6. Hardening of the Recovery Environment
- 7. Document Technical Recovery Scripts
- 8. Test ICT Continuity Plans Regularly
- 9. Establish Performance Monitoring for DR
- 10. Review and Update After Changes
1. Align ICT Recovery Objectives with BIA
Control Requirement: ICT continuity strategies must be based on business requirements (RTO and RPO) identified in the BIA.
Required Implementation Step: Open your technical architecture diagrams alongside the approved Business Impact Analysis. You must manually verify that the engineered recovery times for critical servers (e.g., database restoration speed) are mathematically capable of meeting the RTOs demanded by the business operations.
Minimum Requirement: A gap analysis document highlighting where current technical recovery capabilities fall short of business RTOs.
2. Implement High Availability (HA) at the Component Level
Control Requirement: ICT systems must have sufficient redundancy to meet availability targets.
Required Implementation Step: Log into your load balancers or hypervisors and configure active-active or active-passive failover for critical services. You must demonstrate that the removal of a single node (server or appliance) does not result in a total service outage.
Minimum Requirement: A “pull-the-plug” test log showing automatic failover of a critical service without human intervention.
3. Verify Network Path Diversity
Control Requirement: Connectivity must be resilient against physical link failures.
Required Implementation Step: Trace the physical cabling coming into your server room or review your cloud provider’s zone distribution. You must ensure you are utilising distinct physical routes or separate Availability Zones (AZs) so that a single backhoe digging up a street does not cut both primary and secondary connections.
Minimum Requirement: A traceroute log or physical circuit diagram proving diverse routing for internet connectivity.
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4. Configure Automated Backup Replication
Control Requirement: Data must be available at the alternative site within the defined RPO.
Required Implementation Step: Set up automated, asynchronous replication (e.g., SQL AlwaysOn, rsync, or SAN replication) to a geographically separate location. Check the replication lag logs to ensure data is arriving at the secondary site fast enough to meet the Recovery Point Objective.
Minimum Requirement: A replication status report showing “Time Since Last Sync” is within the RPO limit.
5. Provision Standby Capacity
Control Requirement: The alternative site must have the capacity to handle the production workload.
Required Implementation Step: Perform a stress test or capacity calculation on your Disaster Recovery (DR) environment. You must verify that the standby hardware (CPU, RAM, Storage IOPS) can actually support the full load of the business if production fails, avoiding a “failover to a crawl” scenario.
Minimum Requirement: A capacity planning report confirming DR resources match or exceed peak production utilisation.
6. Hardening of the Recovery Environment
Control Requirement: The recovery environment must be as secure as the primary environment.
Required Implementation Step: Apply the same rigorous patching and configuration management scripts to your DR assets as you do to production. Run a vulnerability scan against the dormant DR environment to ensure it hasn’t become a “soft underbelly” of unpatched legacy code.
Minimum Requirement: A clean vulnerability scan report from the DR subnet dated within the last quarter.
7. Document Technical Recovery Scripts
Control Requirement: Restoration procedures must be explicit and technically feasible.
Required Implementation Step: Write detailed, command-line level “Runbooks” for restarting services in the correct order (e.g., Database first, then Middleware, then Web). Do not write generic statements like “Restore System”; list the exact systemctl start commands and DNS update steps.
Minimum Requirement: A technical Runbook tested by a junior engineer to prove independence from the primary architect.
8. Test ICT Continuity Plans Regularly
Control Requirement: ICT readiness must be verified through realistic testing.
Required Implementation Step: Schedule a technical recovery test where you actually isolate the primary system and force the application to run from the secondary site. Measure the actual time taken to recover and compare it against the RTO.
Minimum Requirement: A Post-Test Report recording the actual wall-clock time for recovery versus the target RTO.
9. Establish Performance Monitoring for DR
Control Requirement: The status of ICT readiness must be continuously monitored.
Required Implementation Step: Add your DR endpoints to your monitoring dashboard (e.g., Nagios, Datadog). You must receive alerts if the DR site goes offline or if replication links fail, treating DR health with the same urgency as production health.
Minimum Requirement: Evidence of active monitoring alerts configured for the secondary site’s availability.
10. Review and Update After Changes
Control Requirement: ICT continuity plans must remain current with architectural changes.
Required Implementation Step: Integrate a “DR Impact Assessment” step into your Change Management process. Every time a new server is deployed or a firewall rule changes in production, you must physically update the corresponding configuration in the DR environment immediately.
Minimum Requirement: A Change Request ticket showing the “Update DR” task was completed before closing the ticket.
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