When multiple ACLs that use the same protocol are applied to an interface, which statement is true?

When multiple ACLs that use the same protocol are applied to an interface, which statement is true?

• A. The first ACL applied will affect traffic
• B. The last ACL applied will affect traffic
• C. All ACLs apply in sequence
• D. None of the ACLs affect traffic

Answer: (B)

The thing being tested is how ACLs are applied to an interface. On a given direction (in or out), you can have only one active ACL at a time. If you apply another ACL in the same direction, it replaces the previously applied one, so the most recently applied ACL is the one that actually governs traffic in that direction. That’s why, when you stack multiple ACLs that filter the same protocol on an interface, the last one you apply determines what passes or is blocked. If you want multiple sets of rules to apply, you must combine them into a single ACL or use a different mechanism (like a policy) to apply them in sequence.

The thing being tested is how ACLs are applied to an interface. On a given direction (in or out), you can have only one active ACL at a time. If you apply another ACL in the same direction, it replaces the previously applied one, so the most recently applied ACL is the one that actually governs traffic in that direction. That’s why, when you stack multiple ACLs that filter the same protocol on an interface, the last one you apply determines what passes or is blocked. If you want multiple sets of rules to apply, you must combine them into a single ACL or use a different mechanism (like a policy) to apply them in sequence.