DBS-C01 Monitoring and Troubleshooting Practice Question
Network Topology
A developer is trying to connect to an RDS for PostgreSQL instance using the endpoint shown in the exhibit. The connection fails with a timeout. Which of the following is the most likely cause?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The security group does not allow inbound traffic on port 5432 from the client IP.
The most likely cause is that the security group does not allow inbound traffic on port 5432 from the client IP, causing a timeout. Option A is incorrect because the endpoint is correctly provided by AWS; an incorrect endpoint would produce a different error. Option B is incorrect because SSL encryption is not required by default; if it were, the error would be an SSL handshake failure, not a timeout. Option D is incorrect because Multi-AZ configurations use the same endpoint; no separate endpoint is needed.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The endpoint address is incorrect.
Why it's wrong here
Incorrect. The endpoint appears valid.
- ✗
The DB instance requires SSL encryption to connect.
Why it's wrong here
Incorrect. SSL is optional unless enforced; timeout is not typical for SSL mismatch.
- ✓
The security group does not allow inbound traffic on port 5432 from the client IP.
Why this is correct
Correct. A timeout often indicates network connectivity issues, such as security group rules blocking the port.
- ✗
The DB instance is in a Multi-AZ configuration and requires a different endpoint.
Why it's wrong here
Incorrect. Multi-AZ uses the same endpoint.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This DBS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the DBS-C01 exam.