A. IPS whitelisting rules require frequent updates to stay current, constantly developing vulnerabilities and newly discovered weaknesses.

B. Whitelisting prevents a possible inadvertent DoS attack against the IPS and supporting log-monitoring systems.

C. Penetration testing of third-party IPS systems often requires additional documentation and authorizations; potentially delaying the time-sensitive test.

D. Testing should focus on the discovery of possible security issues across all in-scope systems, not on determining the relative effectiveness of active defenses such as an IPS.