ISO/IEC 27001:2022 · Technological control
ISO 27001 Annex A 8.21: Security of network services
Quick answer
ISO 27001 Annex A 8.21 (Security of network services) is a technological control. Identify, implement and monitor security mechanisms, service levels and requirements for network services.
What auditors look for
Auditors check that 8.21 is either justified as not applicable in your Statement of Applicability or implemented and working. Typical evidence includes:
- Network service requirements
- Provider agreements
- Monitoring of network services
How to implement 8.21 in practice
- Define security requirements for connectivity providers
- Monitor service levels
- Encrypt traffic across untrusted networks
- Name an owner for 8.21, decide how often it runs and file evidence each time, so the control is audit-ready all year.
Recording 8.21 in the Statement of Applicability
List 8.21 with whether it applies, the reason (usually the risks it treats or a legal or contractual requirement), its implementation status and where the evidence lives. If you exclude it, explain why none of your risks or obligations require it.