350-401 Question 366
Select 2A network administrator is troubleshooting a routing issue in a network using EIGRP. The administrator notices that some routes are not being advertised to other EIGRP neighbors. After further investigation, they find that manual summarization has been configured on one of the routers. Which of the following could be the root cause of the issue?
- A
The summary route overlaps with more specific subnets, causing the specific routes to be suppressed.
- B
The auto-summarization feature is enabled, which is conflicting with the manual summary.
- C
The manual summary address does not match the subnet mask of the summarized routes.
- D
The EIGRP metric for the summarized route is higher than the specific routes, causing it to be ignored.
- E
A routing loop is caused by the manual summarization, leading to route suppression.
Show answer and explanation
Correct answers: A, B
Explanation
When troubleshooting manual summarization in EIGRP, it is important to check for overlapping summary routes and conflicts with auto-summarization. Overlapping summaries can suppress specific routes, while auto-summarization can interfere with manual summary configurations. Understanding how EIGRP handles route summarization is crucial to resolving such issues.
- A. Correct.
Correct. When a summary route overlaps with more specific subnets, the EIGRP process suppresses the specific routes to avoid advertising redundant information.
- B. Correct.
Correct. If auto-summarization is enabled, it can conflict with manually summarized routes, leading to inconsistent or missing route advertisements.
- C. Incorrect.
Incorrect. The subnet mask of the manual summary does not need to match exactly, as summarization involves creating an aggregate route that covers multiple smaller subnets.
- D. Incorrect.
Incorrect. The EIGRP metric might determine route preference but does not explain why specific routes are being suppressed due to summarization.
- E. Incorrect.
Incorrect. Manual summarization, when configured correctly, does not inherently cause routing loops.