ACL Study Guide 2026
Everything you need to pass the ACL exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ACL Exam Format at a Glance
📚 ACL Topics to Study (69)
✍️ Sample ACL Questions & Answers
1. Which of the following best describes confidentiality in Access Control Lists?
Confidentiality involves protecting sensitive information and only sharing it with authorized parties who need it.
2. Under the CIS Benchmarks for network devices, what is the recommended treatment of the ACL 'permit ip any any' rule?
CIS Benchmarks prohibit 'permit ip any any' on external-facing interfaces as it negates all other ACL controls and violates least-privilege.
3. During an ACL penetration test, a tester finds that management interfaces (SSH, SNMP) are not restricted by source IP in the ACL. What is the highest-priority remediation?
Management interfaces should only be reachable from designated management networks; source IP restrictions in ACLs prevent attackers on untrusted networks from reaching these high-value targets.
4. An engineer is implementing ACLs on a Cisco router and notices the implicit deny at the end. What action should be taken to meet logging compliance requirements for denied traffic?
The implicit deny does not generate log entries; adding an explicit 'deny any any log' statement captures denied traffic for compliance logging.
5. A security team reviews ACL logs to meet NIST SP 800-53 AU-2 (Auditable Events) requirements. Which log entries are most critical to capture from ACL devices?
AU-2 requires logging both allowed and denied events; capturing complete ACL flow data (source, destination, port, protocol, time) enables auditing and forensic analysis.
6. Which wildcard mask would match only the host 192.168.10.25?
A wildcard mask of 0.0.0.0 means all bits must match exactly, which is equivalent to specifying a single host.