Quick Answer
The answer is to enable AWS Shield Advanced and implement a web application firewall (WAF) at the edge. AWS Shield Advanced provides dedicated, always-on detection and automatic mitigation against large-scale DDoS attacks targeting your VPC, while AWS WAF filters out malicious application-layer traffic, such as SQL injection or cross-site scripting, before it reaches your resources. On the AWS Certified SysOps Administrator Associate SOA-C02 exam, this pairing tests your understanding that DDoS protection must occur at the network and application layers, not at the instance or subnet level. A common trap is selecting security groups or network ACLs, which are stateful and stateless firewalls respectively but cannot handle the volumetric scale of a DDoS attack. Remember the memory tip: "Shield stops the flood, WAF filters the mud" — Shield handles the massive volume, and WAF scrubs the malicious payloads at the edge.
This SOA-C02 practice question tests your understanding of networking and content delivery. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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.
Which TWO security measures should be implemented to protect a VPC from DDoS attacks? (Choose two.)
Use AWS WAF with rate-based rules
Rate-based rules can block DDoS traffic.
Enable AWS Shield Advanced
Provides enhanced DDoS protection.
Apply network ACLs with deny rules
Why wrong: NACLs are stateless and limited in DDoS mitigation.
Use restrictive security groups
Why wrong: Security groups help but are not sufficient for DDoS.
Enable VPC Flow Logs
Why wrong: Flow Logs are for monitoring, not protection.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Use AWS WAF with rate-based rules
AWS Shield Advanced provides DDoS protection. Using a web application firewall (WAF) at the edge helps filter malicious traffic. Security groups and NACLs are not effective against DDoS at scale.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Use AWS WAF with rate-based rules
Why this is correct
Rate-based rules can block DDoS traffic.
Related concept
Standard ACLs match source addresses.
Enable AWS Shield Advanced
Why this is correct
Provides enhanced DDoS protection.
Related concept
Standard ACLs match source addresses.
Apply network ACLs with deny rules
Why it's wrong here
NACLs are stateless and limited in DDoS mitigation.
Use restrictive security groups
Why it's wrong here
Security groups help but are not sufficient for DDoS.
Enable VPC Flow Logs
Why it's wrong here
Flow Logs are for monitoring, not protection.
Common exam traps
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Detailed technical explanation
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Real-world example
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related SOA-C02 ACL questions on filtering logic and placement.
Networking and Content Delivery — study guide chapter
Learn the concepts, then practise the questions
Networking and Content Delivery practice questions
Targeted practice on this topic area only
All SOA-C02 questions
1,546 questions across all exam domains
AWS Certified SysOps Administrator Associate SOA-C02 study guide
Full concept coverage aligned to exam objectives
SOA-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise SOA-C02 questions linked to Monitoring, Logging, and Remediation.
Practise SOA-C02 questions linked to Reliability and Business Continuity.
Practise SOA-C02 questions linked to Deployment, Provisioning, and Automation.
Practise SOA-C02 questions linked to Security and Compliance.
Practise SOA-C02 questions linked to Networking and Content Delivery.
Practise SOA-C02 questions linked to Cost and Performance Optimization.
Practise SOA-C02 questions linked to SOA-C02 fundamentals.
Practise SOA-C02 questions linked to SOA-C02 scenario.
Practise SOA-C02 questions linked to SOA-C02 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Networking and Content Delivery — This question tests Networking and Content Delivery — Standard ACLs match source addresses..
The correct answer is: Use AWS WAF with rate-based rules — AWS Shield Advanced provides DDoS protection. Using a web application firewall (WAF) at the edge helps filter malicious traffic. Security groups and NACLs are not effective against DDoS at scale.
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related SOA-C02 ACL questions on filtering logic and placement.
Standard ACLs match source addresses.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 20, 2026
This SOA-C02 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 SOA-C02 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.