ACL Rules Simulator
Security
Overview
Ordered ACLs evaluate source, destination, protocol and ports. First matching rule controls the result; an implicit deny commonly applies at the end. Broad early rules can shadow specific later ones. Test allowed and forbidden flows, not only one success case.
Protocol stages
- 1Flow tuple
- 2Rule 1
- 3Rule 2
- 4First match
- 5Implicit deny
Interactive exercise
Knowledge check
Rules: deny any any first, allow TCP/443 from LAN second. What happens to LAN HTTPS?
Related practice
Lab: firewall-allowEducational model — not real hardware, traffic or official certification.