200-301 Question 416
Single answerA network engineer is troubleshooting access control issues in a corporate network. The engineer has configured an access control list (ACL) on a router to block HTTP traffic from a specific subnet (192.168.1.0/24) to a web server (10.1.1.1). After applying the ACL, the engineer notices that the HTTP traffic is still not being blocked. What could be the most likely cause of this issue?
- A
The ACL was not applied to the correct interface.
- B
The ACL is using the wrong protocol in its rules.
- C
The web server is not configured to accept HTTP traffic.
- D
The ACL rules are in the wrong order.
Show answer and explanation
Correct answer: A
Explanation
Access Control Lists (ACLs) need to be applied to the correct interface and direction (inbound or outbound) to function as intended. In this case, the most likely issue is that the ACL was not applied to the appropriate interface. Before troubleshooting other potential issues, it is crucial to verify that the ACL is implemented in the correct location and direction on the router.
- A. Correct.
If the ACL is not applied to the correct interface or direction (inbound or outbound), it will not take effect and will not block traffic as intended. This is the most likely cause in this scenario.
- B. Incorrect.
While using the wrong protocol could cause issues, this scenario specifies that the ACL was configured to block HTTP traffic, which generally uses TCP port 80. Therefore, this is less likely to be the issue here.
- C. Incorrect.
The web server's configuration would not affect the ACL's ability to block traffic. The issue lies within the ACL configuration, not the server.
- D. Incorrect.
While ACL rules being in the wrong order could cause unexpected behavior, the scenario does not provide any indication of conflicting rules or rule order issues.