While preparing for the GCP Professional Cloud Architect (PCA) exam, many candidates stumble on effectively enabling network security observability. In the real world, this is fundamentally a decisions about balancing log volume cost, IAM permissions, and observability completeness. Let’s drill into a simulated scenario.
The Scenario #
FinEdge Finance is a fast-growing fintech startup providing micro-investment platforms to global users. To secure their Compute Engine environment, they implemented several firewall rules managed in Google Cloud’s Virtual Private Cloud (VPC). For ongoing security posture monitoring and incident response, FinEdge uses the Firewall Insights feature within Google Cloud’s Network Intelligence Center (NIC) to analyze firewall rule efficiency and detect misconfigurations.
Recently, FinEdge’s security operations team noticed the Firewall Insights dashboard shows no firewall event logs despite traffic flowing through the Compute Engine instances and firewall rules applied.
Key Requirements #
FinEdge’s cloud architect must troubleshoot why Firewall Insights shows no data, ensuring effective firewall logging and visibility, while controlling log cost and adhering to least privilege principles in IAM.
The Options #
- A) Enable Virtual Private Cloud (VPC) flow logging on the subnetworks where Compute Engine instances reside.
- B) Enable Firewall Rules Logging on each specific firewall rule you want to monitor.
- C) Verify your user account has been granted the IAM role compute.networkAdmin to access firewall logs.
- D) Install the Google Cloud SDK locally and check for firewall logs by querying logs via the command line.
Correct Answer #
B) Enable Firewall Rules Logging on each specific firewall rule you want to monitor.
The Architect’s Analysis #
Correct Answer #
Option B: Enable Firewall Rules Logging on each specific firewall rule you want to monitor.
Step-by-Step Winning Logic #
Firewall Insights relies specifically on logs generated by firewall rules themselves, not on broader VPC flow logs. The most granular and cost-effective way to gather these logs is to explicitly enable logging at the firewall rule level. This targeted logging aligns with SRE’s principle of observability with minimal toil and FinOps-driven cost optimization. Centrally enabling VPC flow logs (Option A) can create a much larger volume of data, increasing cost and noise. Ensuring appropriate IAM permissions (Option C) is necessary, but missing logs won’t be corrected by permissions alone. Option D is an operational troubleshooting step but does not solve the root cause.
The Traps (Distractor Analysis) #
- Why not A? VPC flow logs capture metadata about network flows but do not directly support Firewall Insights visualization nor provide firewall rule-specific logging.
- Why not C? Even without networkAdmin role, logs may be produced; permission issues only affect viewing but not the presence of logs in Firewall Insights.
- Why not D? Using Cloud SDK to query logs is a valid investigation step but does not enable logging if it wasn’t already configured.
The Architect Blueprint #
- Mermaid Diagram illustrating the correct logging flow for Firewall Insights.
- Diagram Note: Firewall rule logging is enabled per firewall rule, sending logs into Cloud Logging, enabling the Firewall Insights dashboard to visualize security data effectively.
The Decision Matrix #
| Option | Est. Complexity | Est. Monthly Cost | Pros | Cons |
|---|---|---|---|---|
| A) Enable VPC Flow Logs | Medium | Medium to High (Logs all traffic metadata) | Broad traffic visibility | Generates high log volume, costly, unrelated to firewall rule specific insights |
| B) Enable Firewall Rules Logging | Low | Low to Medium (Selective logs only for chosen rules) | Targeted logging, efficient, cost-effective | Must be enabled per rule, potential for overlooked logging if missed |
| C) IAM Role compute.networkAdmin | Low | None | Required for full visibility & management | Does not enable logging, only permits access |
| D) Use Cloud SDK to Inspect Logs | Low | None | Useful for live troubleshooting | Does not enable logging or fix missing logs |
Real-World Practitioner Insight #
Exam Rule #
For the exam, always pick enable logging at specific firewall rules when you see Firewall Insights and need visibility into firewall efficiency.
Real World #
In practical scenarios, many enterprises default to VPC Flow Logs for network monitoring, but for targeted firewall troubleshooting with FinOps constraints, enabling firewall rule logs selectively avoids excessive logging costs and data overload while adhering to least privilege access patterns.