# ISO/IEC 27001:2022 A.8.20 — Networks security

- Source: https://support.icompaas.com/compliance/iso-27001-2022/a-8-20-networks-security
- Section: [Compliance](https://support.icompaas.com/compliance) › [ISO/IEC 27001:2022 Annex A Controls](https://support.icompaas.com/compliance/iso-27001-2022) › Technological controls
- Last updated: 2026-06-05
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

**ISO/IEC 27001:2022**·Annex A `A.8.20`·high·Component: **Technological controls**

## What this control requires

> Networks and network devices shall be secured, managed and controlled to protect information in systems and applications.
> 
> — ISO/IEC 27001:2022, Annex A A.8.20

### In plain English

Networks and network devices shall be secured, managed and controlled to protect information in systems and applications. In practice, this means you can prove you information information-level controls on a defined cadence.

## Why it matters

ISO 27001 certification depends on showing each Annex A control is either implemented or explicitly justified for exclusion in the Statement of Applicability (SoA). Certification bodies sample controls during surveillance audits, and a missing SoA entry — or implementation that doesn't match the SoA wording — is a finding.

This control is rated **high**. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation.

## What an auditor looks for

An ISO 27001 lead auditor looks for: (1) an SoA entry covering the control with justification, (2) a documented procedure or policy implementing it, (3) records that prove the procedure runs (logs, tickets, training records) and (4) management-review evidence that effectiveness is monitored.

Within **Technological controls**, the assessor will trace your implementation back to the catalogue reference (Annex A A.8.20) and look for objective evidence on the latest two assessment cycles.

## How to implement

#### Endpoint Protection

**MDM.** Make MDM enrollment a hard gate for device access (Intune compliance + Conditional Access, or Jamf + Okta device trust). Unmanaged devices simply don't get a session token.

**EDR.** Deploy CrowdStrike / SentinelOne / Defender for Endpoint to every server and laptop; alert on any host that stops sending telemetry for >24h.

#### Network Security

**AWS.** VPC Flow Logs to S3, default-deny security groups, AWS Network Firewall for north-south, and Transit Gateway for hub-and-spoke segmentation.

**Azure.** NSGs with deny-by-default, Azure Firewall Premium with TLS inspection, Private Endpoints for PaaS, and Microsoft Defender for Cloud's secure score for drift.

**GCP.** VPC Service Controls perimeters around sensitive APIs, Cloud NGFW Enterprise for L7 inspection, Private Service Connect for managed services.

### Operational checklist

-   **Information.** Document the trigger, the owner and the cadence.
-   **Protection.** Document the trigger, the owner and the cadence.
-   **Protect.** Document the trigger, the owner and the cadence.
-   **Security.** Document the trigger, the owner and the cadence.
-   **Networks.** Document the trigger, the owner and the cadence.
-   **Scope:** information, security, networks.

## Evidence to collect

-   **Infra Scan.** Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings.

Network posture platforms (Prisma Cloud, Defender for Cloud) validate firewall, IDS and segmentation controls.

## Common pitfalls

-   Pilot MDM rollouts that quietly exclude executives or engineers; carving out the highest-risk users is the most common audit failure.
-   Default-allow egress rules; East-West traffic with no segmentation; jump hosts on the public internet with password auth.

## How it maps to other frameworks

Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.

-   [**NIST SP 800-53 Rev. 5 PE-5(3)** — Marking Output Devices](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/pe-5-3-marking-output-devices)

## Related controls in ISO/IEC 27001:2022

-   [**Annex A A.8.10** — Information deletion](https://support.icompaas.com/compliance/iso-27001-2022/a-8-10-information-deletion)
-   [**Annex A A.8.16** — Monitoring activities](https://support.icompaas.com/compliance/iso-27001-2022/a-8-16-monitoring-activities)
-   [**Annex A A.8.22** — Segregation of networks](https://support.icompaas.com/compliance/iso-27001-2022/a-8-22-segregation-of-networks)
-   [**Annex A A.8.26** — Application security requirements](https://support.icompaas.com/compliance/iso-27001-2022/a-8-26-application-security-requirements)

## References

-   [ISO/IEC JTC 1/SC 27 — ISO/IEC 27001:2022](https://www.iso.org/standard/27001)
-   Catalogue identifier: `Annex A A.8.20`

Topics: endpoint securityendpoint protectionnetwork security

## Related compliance guidance

- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): Start with the full ISO 27001 implementation guide — scope, roadmap, evidence and how the assessment runs.
- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most companies that hold ISO 27001 also need a SOC 2 report for North American customers, and the two share most of their technical controls.