350-401 Question 363
Single answerA network engineer is troubleshooting a routing issue in an OSPF environment. The engineer notices that manual route summarization has been applied at an ABR, but some subnets are missing from the OSPF database in one of the areas. What could be causing this issue?
- A
The subnets being summarized are not included in the network statements of the OSPF process.
- B
The manual summarization is configured on the wrong interface.
- C
The summarized route has a lower metric than the specific subnets, causing the subnets to be suppressed.
- D
The OSPF area type is configured as a stub or totally stubby area, which does not support summarization.
Show answer and explanation
Correct answer: A
Explanation
In OSPF, manual summarization can only summarize the networks that are included in the OSPF process through network statements. If the subnets being summarized are missing from the OSPF database, it is likely because they were not included in the OSPF network statements. Proper configuration of network statements is critical for the summarization process to function correctly.
- A. Correct.
If the subnets being summarized are not included in the OSPF network statements, they will not be advertised into the OSPF database, leading to missing routes.
- B. Incorrect.
Manual summarization is applied on ABRs for specific areas and not on individual interfaces. This option is incorrect as summarization configuration is not interface-specific in OSPF.
- C. Incorrect.
OSPF does not suppress specific subnets in favor of summarized routes based on metric. Both specific and summarized routes can coexist in the OSPF database.
- D. Incorrect.
Stub and totally stubby areas restrict certain types of LSAs, but they do not prevent summarization. Summarization can still occur at ABRs for these areas.