What evidence do auditors commonly ask for on 8.20 Networks security?

Current network diagrams and device configuration backups for routers, switches, firewalls and wireless controllers; Defined responsibilities and procedures for network device management, separated from system operations where appropriate; Firewall rule sets, network access control configuration and device authentication (for example 802.1X) restricting what can connect; Hardening standards for network devices and evidence that insecure protocols are disabled; A segregated management network or out-of-band administration channel; Network logs and monitoring coverage, and encryption of data crossing public, third-party or wireless networks.

What is the most common gap auditors find on 8.20?

Network diagrams are years out of date

ISO/IEC 27002:2022 · Technological controls

`8.20` Networks security

Networks and network devices are to be secured, managed and controlled so that information in systems and applications is protected. Purpose: protect information in networks and the facilities that support it from being compromised through the network. Guidance: implement controls that secure information in networks and protect connected services from unauthorized access, considering: the kinds and classification of information the network can carry; responsibilities and procedures for managing network equipment and devices; current documentation including network diagrams and device configuration files for routers, switches and similar; where suitable, keeping network operations under different responsibility from running ICT systems (5.3); controls protecting the confidentiality and integrity of data over public, third-party or wireless networks and protecting connected systems and applications (5.22, 8.24, 5.14, 6.6), plus measures for availability of network services and connected computers; logging and monitoring that records and detects security-relevant actions (8.15, 8.16); close coordination of network management so service is optimized and controls are applied consistently across the infrastructure; authenticating systems on the network; restricting and filtering system connections, for example with firewalls; detecting, restricting and authenticating equipment and devices connecting to the network; hardening network devices; separating network administration channels from other traffic; being able to isolate critical subnetworks temporarily if the network is attacked; and disabling vulnerable network protocols. Apply suitable security to virtualized networks, including software-defined networking and SD-WAN, which can help by logically separating communications over shared physical networks, especially for distributed systems. Other information: see the ISO/IEC 27033 series and ISO/IEC TS 23167.

Source: ISO/IEC 27002:2022, 8.20. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open ISO/IEC 27002:2022 in the compliance library.

ISO/IEC 27002 is guidance on the Annex A controls; certification is against ISO/IEC 27001. Use this set when your sheet follows the 27002 numbering.

artefacts

held by a system

at each review

easy

to go live

Backup / DR tooling

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Current network diagrams and device configuration backups for routers, switches, firewalls and wireless controllers · Backup / DR tooling
Firewall rule sets, network access control configuration and device authentication (for example 802.1X) restricting what can connect · Endpoint management (MDM / EDR)
Network logs and monitoring coverage, and encryption of data crossing public, third-party or wireless networks · SIEM / log platform

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

Defined responsibilities and procedures for network device management, separated from system operations where appropriate · Policy repository / GRC workspace
Hardening standards for network devices and evidence that insecure protocols are disabled · Policy repository / GRC workspace
A segregated management network or out-of-band administration channel · Policy repository / GRC workspace

First move

Automate the pull from your Backup / DR tooling. Backup job success history and restore-test logs from the backup platform.

Common gaps auditors find

Network diagrams are years out of date
Management interfaces of network devices are reachable from user networks
Unknown devices can connect to wired ports without any authentication
Legacy protocols such as Telnet or SNMPv1 remain enabled

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

8.19 Installation of software on operational systems · 8.21 Security of network services