200-301 Question 434
Single answerA network administrator is tasked with configuring an access control list (ACL) on a router to deny HTTP and HTTPS traffic from the 192.168.10.0/24 network to the 10.0.0.0/24 network, while permitting all other traffic. After applying the ACL to the correct interface in the inbound direction, the administrator notices that all traffic from 192.168.10.0/24 to 10.0.0.0/24 is being denied. What could be the issue with the ACL configuration?
- A
The ACL is missing a permit statement for other traffic.
- B
The ACL needs to be applied in the outbound direction instead.
- C
The deny statements for HTTP and HTTPS are incorrectly written.
- D
The ACL lacks an implicit deny rule at the end.
Show answer and explanation
Correct answer: A
Explanation
In this scenario, the ACL is likely missing a 'permit' statement for other traffic after the 'deny' statements for HTTP and HTTPS. ACLs have an implicit 'deny all' at the end, so without an explicit 'permit' for other traffic, all traffic from the source network to the destination network is denied, regardless of whether it matches the deny conditions or not. The administrator should add a 'permit ip any any' statement at the end of the ACL to allow all other traffic.
- A. Correct.
Correct. ACLs require an explicit permit statement to allow desired traffic; otherwise, all traffic is implicitly denied.
- B. Incorrect.
Incorrect. The direction of the ACL application is not the issue in this scenario, as it is correctly applied in the inbound direction.
- C. Incorrect.
Incorrect. If the deny statements were incorrectly written, HTTP and HTTPS traffic would not be blocked, which is not the issue described here.
- D. Incorrect.
Incorrect. All ACLs already have an implicit deny rule at the end by default, so this is not the problem.