CCNA Network Services and Security Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Step 1: Define the ACL with permit and deny statements. Step 2: Apply the ACL inbound on GigabitEthernet0/1. Step 3: Verify the ACL configuration.

  Why this is correct

  This is the correct order: first create the ACL with the required permit and deny statements, then apply it to the interface in the inbound direction, and finally verify the configuration to ensure it is working as intended.

• ✗

  Step 1: Apply the ACL inbound on GigabitEthernet0/1. Step 2: Define the ACL with permit and deny statements. Step 3: Verify the ACL configuration.

  Why it's wrong here

  Attempting to apply an ACL before it has been defined is invalid because the 'ip access-group' command references an existing ACL object; with no ACL in the configuration, the interface either rejects the binding or silently installs a filter that does not match the intended traffic. Ordering is critical: the ACL with its permit and deny statements must be created first, otherwise there are no rules for the interface to evaluate. Thus, this sequence violates the fundamental create-before-use rule and cannot produce the desired filtering.

• ✗

  Step 1: Define the ACL with permit and deny statements. Step 2: Verify the ACL configuration. Step 3: Apply the ACL inbound on GigabitEthernet0/1.

  Why it's wrong here

  Verifying the ACL immediately after defining it but before applying it to GigabitEthernet0/1 checks only the syntax and order of the ACEs, not whether traffic is actually filtered on the live interface. A configuration can look correct in 'show access-lists' yet still fail once bound, for example if the implicit deny or an incorrect protocol match interferes with traffic. The verification step is meaningful only after the ACL is applied, because commands like 'show ip access-group' and interface-specific counters confirm that the ACL is both present and selecting the correct inbound packets.

• ✗

  Step 1: Apply the ACL inbound on GigabitEthernet0/1. Step 2: Verify the ACL configuration. Step 3: Define the ACL with permit and deny statements.

  Why it's wrong here

  This sequence is completely reversed: the ACL is applied to the interface before it exists, making the binding either fail or have no effect, and the later verification step cannot validate an undefined or non-existent ACL. Defining the ACL only at the very end means the interface was never actually protected during the process, and any verification performed earlier would have shown nothing useful. Each operation depends on the previous one, so applying first, then verifying, then defining contradicts the correct logical dependency chain and leaves the network exposed.

Option-by-option analysis

Why each answer is right or wrong

Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.

Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”