PCNE Practice Question: Managing, Monitoring, and Optimising Network Operations
A company uses VPC Flow Logs to analyze traffic patterns. They notice that the logs show only 50% of the actual flows. What 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 default sampling rate of 50% is applied.
By default, VPC Flow Logs sample 50% of flows. This is a known behavior and can be adjusted by configuring the sampling rate.
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 subnet does not have Flow Logs enabled.
Why it's wrong here
If Flow Logs were not enabled, no logs would be generated.
- ✓
The default sampling rate of 50% is applied.
Why this is correct
VPC Flow Logs sample only 50% of flows by default.
- ✗
Flow Logs are only generated for incoming traffic.
Why it's wrong here
Flow Logs capture both incoming and outgoing traffic.
- ✗
Logs are being filtered by a log sink.
Why it's wrong here
A log sink would exclude logs from Cloud Logging, not reduce the number of flows logged.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PCNE practice question is part of Courseiva's free Google Cloud 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 PCNE exam.