300-440 Question 11
Single answerA network engineer has configured a route map to filter specific routes advertised from one OSPF area to another. However, upon verification, the filtered routes are still being advertised. Which of the following could be the cause of this issue?
- A
The route map is not applied to the correct OSPF process.
- B
The route map does not include a 'permit' statement for allowed routes.
- C
The route map is missing a sequence number.
- D
The route map is applied in the wrong direction (inbound instead of outbound).
Show answer and explanation
Correct answer: D
Explanation
Route maps must be applied in the correct direction (inbound or outbound) depending on the intended filtering purpose. If the direction is incorrect, the routes may not be filtered as expected, leading to undesired results in the routing table or advertised routes. In this scenario, applying the route map in the wrong direction is the most likely cause of the issue.
- A. Incorrect.
If the route map is not applied to the correct OSPF process, no filtering would occur at all. However, in this scenario, filtering is only partially failing, indicating this is not the issue.
- B. Incorrect.
Route maps must have a 'permit' statement for routes that should be allowed. However, the issue described is that routes are incorrectly being advertised, so this is not the root cause.
- C. Incorrect.
While sequence numbers are important for the order of operations in route maps, missing one does not result in the route map failing to apply entirely.
- D. Correct.
Applying a route map in the wrong direction (e.g., inbound instead of outbound) is a common misconfiguration that can cause routes to be filtered incorrectly or not at all.