What evidence do auditors commonly ask for on 32 Network-based IDS/IPS (Limited)?

IDS rule tuning log showing noisy signatures adjusted or suppressed, with the reason and approver; Network diagram marking NIDS/NIPS sensor placement at internet gateways and key internal segment boundaries; Signature update logs and heuristic or anomaly detection settings exported from the IDS management console; Sample of network IDS alerts with analyst disposition and any blocking actions applied.

What is the most common gap auditors find on 32?

Sensors placed only at the internet perimeter, blind to east-west traffic between internal segments

ASD Strategies to Mitigate Cyber Security Incidents · Detecting Cyber Security Incidents and Responding

`32` Network-based IDS/IPS (Limited)

Network-based intrusion detection/prevention system using signatures and heuristics to identify anomalous traffic.

Source: ASD Strategies to Mitigate Cyber Security Incidents, 32. 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 ASD Strategies to Mitigate Cyber Security Incidents in the compliance library.

artefacts

held by a system

at each review

easy

to go live

SIEM / log platform

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

IDS rule tuning log showing noisy signatures adjusted or suppressed, with the reason and approver · SIEM / log platform
Signature update logs and heuristic or anomaly detection settings exported from the IDS management console · SIEM / log platform

periodic reviewEvidence produced at each review

Sample of network IDS alerts with analyst disposition and any blocking actions applied · SIEM / log platform

governing documentDocuments that govern the control

Network diagram marking NIDS/NIPS sensor placement at internet gateways and key internal segment boundaries · Policy repository / GRC workspace

First move

Automate the pull from your SIEM / log platform. Retention and alert rules exported from the SIEM; review evidence is the closed-alert record with reviewer and time.

Common gaps auditors find

Sensors placed only at the internet perimeter, blind to east-west traffic between internal segments
Signature feeds expired or subscription lapsed so rules are months out of date
Encrypted traffic passes uninspected, with no TLS inspection or alternative detection method in place

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

31 Hunt to discover incidents (Very Good) · 33 Capture network traffic (Limited)