The answer is to lower the sensitivity level or exclude specific request attributes in the Cloud Armor WAF rule. This is correct because the preconfigured `sqli-stable` rule uses a default sensitivity that can be too aggressive, flagging benign patterns as SQL injection attempts and causing false positives. By adjusting the `sensitivity` parameter—for instance, from a level of 4 down to 2—you reduce the rule’s strictness, while `exclude` lists allow you to bypass inspection on trusted headers, cookies, or URI paths. On the Google Professional Cloud Network Engineer exam, this scenario tests your ability to fine-tune WAF rules without disabling security; a common trap is to assume you must rewrite custom rules or lower the entire policy’s action to "allow." Remember the mnemonic **S.E.A.** — Sensitivity, Exclude, Adjust — to recall the three levers for mitigating false positives in Cloud Armor.
PCNE Configuring network services Practice Question
This PCNE practice question tests your understanding of configuring network services. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Your security team wants to block specific SQL injection attacks using Cloud Armor. You have configured a security policy with a preconfigured WAF rule for SQL injection (evaluatePreconfiguredExpr('sqli-stable')). The rule is set to DENY. However, legitimate traffic is being blocked intermittently. What should you adjust?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Modify the WAF rule to use a lower sensitivity level or exclude certain request attributes.
The preconfigured WAF rule for SQL injection (sqli-stable) uses a default sensitivity level that may be too aggressive, causing false positives on legitimate traffic. By lowering the sensitivity level or excluding specific request attributes (e.g., headers, cookies, or URI paths), you can reduce false positives while still blocking actual SQL injection attempts. Cloud Armor allows fine-tuning of preconfigured rules via the `sensitivity` parameter and `exclude` lists, which is the correct approach here.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Add a rate-based rule to limit the number of requests per second.
Why it's wrong here
Rate limiting won't fix false positives for SQLi.
✗
Create a rule with higher priority to allow the legitimate traffic before the WAF rule.
Why it's wrong here
Allow rules with higher priority can override, but that would allow all traffic unless very specific.
✓
Modify the WAF rule to use a lower sensitivity level or exclude certain request attributes.
Why this is correct
Reducing sensitivity reduces false positives.
Related concept
Read the scenario before looking for a memorised answer.
✗
Enable TLS inspection for the load balancer to fully inspect encrypted traffic.
Why it's wrong here
TLS inspection is a separate feature and not directly related to false positives.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Google Cloud often tests the misconception that false positives from WAF rules are best handled by adding allow rules or rate limiting, rather than tuning the rule's sensitivity or exclusions, which is the proper Cloud Armor mechanism.
Detailed technical explanation
How to think about this question
Cloud Armor's preconfigured WAF rules use a set of regex patterns based on the ModSecurity Core Rule Set (CRS) to detect SQL injection. The sensitivity level (e.g., 1-4) controls how many of these patterns must match before the rule triggers; a lower sensitivity requires more matches, reducing false positives. Excluding attributes like `user-agent` or `referer` can prevent legitimate requests with SQL-like strings in those fields from being blocked, which is common in API calls or search queries.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Configuring network services — This question tests Configuring network services — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Modify the WAF rule to use a lower sensitivity level or exclude certain request attributes. — The preconfigured WAF rule for SQL injection (sqli-stable) uses a default sensitivity level that may be too aggressive, causing false positives on legitimate traffic. By lowering the sensitivity level or excluding specific request attributes (e.g., headers, cookies, or URI paths), you can reduce false positives while still blocking actual SQL injection attempts. Cloud Armor allows fine-tuning of preconfigured rules via the `sensitivity` parameter and `exclude` lists, which is the correct approach here.
What should I do if I get this PCNE question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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