Intrusion Detection and Prevention Systems evaluation questionnaire

1. RFIDoes the platform operate in IDS (detect-only), IPS (inline, block), or both modes, and what is the process for safely transitioning a newly deployed sensor from detect-only to active blocking without disrupting legitimate traffic?
   Answer key — what a strong answer shows

   Jumping straight to inline blocking risks outages from false positives — look for a described monitor-then-enforce rollout process, not an assumption that blocking mode is safe from day one.

2. RFPDescribe detection methodology — signature-based, anomaly/behavioral, or both — and provide a measured false-positive rate and detection rate against current threats (not just historical signature coverage counts) from independent testing if available.
   Answer key — what a strong answer shows

   Signature count alone doesn't indicate detection quality; look for independent testing results (e.g., NSS Labs-style or vendor-disclosed) covering both detection rate and false-positive rate together.

3. RFIWhat is the throughput at full inspection depth — including SSL/TLS decryption and deep packet inspection enabled — versus the marketed maximum, and how does latency change under sustained peak load?
   Answer key — what a strong answer shows

   Marketed throughput often assumes minimal inspection; look for a real-world figure with full decryption/DPI enabled, since that's the actual production configuration for most deployments.

4. RFIHow does the platform handle encrypted traffic — full TLS decryption/re-encryption, or encrypted-traffic-analysis without decryption — and what are the privacy/compliance implications of the chosen approach for regulated traffic?
   Answer key — what a strong answer shows

   Full decryption raises privacy/compliance questions (especially for regulated data); look for the vendor addressing this tradeoff directly, including any selective-decryption/bypass-list capability for sensitive traffic classes.

5. RFPDetail signature/rule update cadence and the process for rapid emergency updates when a critical new threat (e.g., mass-exploited CVE) is disclosed — what is the typical time from public disclosure to a protective signature being available and deployed?
   Answer key — what a strong answer shows

   Look for a stated time-to-signature figure for emergency threats, plus confirmation of automatic (not manual-download) deployment — stale signatures leave known-exploited gaps open.

6. RFIWhat is the false-positive tuning workflow — can an analyst suppress a specific false positive permanently without disabling the broader signature/rule, and is tuning centrally managed across a fleet of sensors?
   Answer key — what a strong answer shows

   Look for surgical, centrally-managed suppression — broad rule-disabling to kill one false positive quietly reopens real coverage gaps.

7. RFPExplain high-availability deployment — active/active or active/passive sensor pairs, behavior during a sensor failure (fail-open passing traffic uninspected, or fail-closed blocking all traffic), and whether this is configurable per deployment.
   Answer key — what a strong answer shows

   Fail-open vs. fail-closed is a critical, deployment-specific decision (uptime vs. security posture) — look for it being explicitly configurable, not a fixed vendor default the buyer can't change.

8. RFIHow does the platform integrate with SIEM/SOAR for automated response beyond blocking — can a detection trigger broader actions (endpoint isolation, firewall rule updates, ticket creation) via integration, not just local alerting?
   Answer key — what a strong answer shows

   Look for real orchestration integration extending response beyond the IDS/IPS's own inline action, not just log forwarding requiring manual SOC correlation.

9. RFIWhat is the pricing/licensing model — perpetual hardware license, subscription, or throughput-tiered — and are signature updates/threat-intelligence feeds bundled or a separate paid subscription on top of the base platform?
   Answer key — what a strong answer shows

   Look for transparent, explicit disclosure of what's bundled versus a paid add-on; signature/threat-intel updates gated behind a separate subscription is a common way buyers underestimate real total cost.

10. RFPWhat virtual/cloud-native deployment options exist (VM-based, cloud-marketplace images) as an alternative to physical hardware sensors, and is feature/detection parity maintained between hardware and virtual form factors?
    Answer key — what a strong answer shows

    Look for an explicit answer on feature parity — virtual form factors sometimes lag behind hardware sensors in detection capability, which matters for a customer building a hybrid or cloud-first architecture.

11. RFIFor a real, successfully-blocked intrusion attempt, what forensic detail is captured (full packet capture, not just an alert summary) sufficient to support a genuine incident investigation, and what is the retention period for that forensic data?
    Answer key — what a strong answer shows

    A blocked attack still deserves full forensic investigation to understand intent/scope — ask for a specific answer on captured forensic depth and retention, not just confirmation that the attack was blocked.

12. RFIWhat compliance/security certifications does the platform hold (Common Criteria, FIPS 140-2/140-3) given its inline network position, and can the customer request the actual validation certificate rather than accepting an unqualified compliance claim?
    Answer key — what a strong answer shows

    A device sitting inline on network traffic is significant security infrastructure — insist on the real validation certificate/level, not just a logo or unqualified 'certified' claim.

13. RFPHow is detection consistency maintained across a large, multi-site/branch-office deployment — are signature updates and tuning changes centrally pushed and synchronized fleet-wide, or can sensors drift out of sync at less-actively-managed sites?
    Answer key — what a strong answer shows

    Ask for a specific answer on centralized, synchronized management at scale; sensor drift at less-actively-managed remote sites is a common real gap for large distributed organizations.

14. RFPDetail historical trend reporting on threat volume and blocked-attack trends over time, suitable for demonstrating security posture and ROI to executive/board audiences, distinct from a real-time technical alert dashboard.
    Answer key — what a strong answer shows

    Trend-over-time reporting suitable for board audiences is a distinct capability from a real-time dashboard built for security engineers — confirm this exists as a maintained, exportable report.

15. RFIWhat is a customer-referenced migration timeline and process for replacing an incumbent IDS/IPS vendor (rule/policy translation tooling, parallel-run period, cutover risk mitigation)?
    Answer key — what a strong answer shows

    Strong answers describe real migration tooling and a concrete, customer-validated timeline; a vendor with no migration story is asking the customer to manually rebuild potentially years of accumulated signature tuning from scratch.

16. RFIHow does this platform's IPS capability relate to the IPS/threat-prevention module already built into many NGFW products — is this a genuinely distinct, complementary layer, or does it substantially duplicate what the customer's existing NGFW already provides?
    Answer key — what a strong answer shows

    This is a real, common buyer question given the functional overlap between standalone IDS/IPS and NGFW's own threat-prevention module — a vendor should give an honest answer about the boundary and complementarity, not imply a standalone purchase is always necessary.

Verified buyers can suggest criteria (anonymized before pooling).