CLF-C02 Amazon Web Services AWS Certified Cloud Practitioner Free Practice Exam Questions (2025 Updated)

AWS WAF Overview:

AWS Web Application Firewall (WAF) allows users to create rules to block or allow traffic based on IP addresses, request patterns, and other conditions.

It is ideal for blocking traffic from a specific IP address.

Why AWS WAF Meets the Requirement:

The company can create a WAF rule to block traffic from the malicious IP address.

WAF integrates with services like Amazon CloudFront, Application Load Balancer, and API Gateway.

Why Other Options Are Incorrect:

A. AWS Shield:Protects against DDoS attacks but does not allow custom IP blocking.

B. AWS Config:Monitors resource configurations but does not block IPs.

C. Amazon GuardDuty:Detects threats but does not block traffic directly.

Elastic Load Balancing (ELB) distributes incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, ensuring better application availability and fault tolerance. While ELB scales to meet traffic demands, it does not inherently scale compute resources themselves, span multiple regions, or balance traffic between internet gateways.

AWS IAM Identity Center (formerly AWS Single Sign-On) provides centralized management of user access to multiple AWS accounts within an organization in AWS Organizations. It allows users to log in once and gain access to all assigned accounts without managing separate logins for each account. Amazon Cognito is generally used for application-level user management and authentication, not for managing access across AWS accounts.

AWS Application Discovery Service helps companies gather information about on-premises data centers to support migration planning. It collects data on system configuration, resource utilization, and network dependencies, providing essential insights for migration. AWS DataSync and Storage Gateway are used for data transfer, while AWS DMS is for database migration specifically.

AWS DataSync is designed for large-scale data transfers, especially involving large datasets with millions of files from on-premises to AWS. It provides fast and efficient transfer capabilities, and supports a one-time migration. AWS DMS is specific to databases, while Migration Hub is for tracking migrations, and Application Migration Service is for continuous replication rather than one-time file migrations.

AWS WAF is a web application firewall that helps protect applications from SQL injection attacks and other common web exploits. By defining rules to block, allow, or monitor specific types of requests, AWS WAF provides an effective defense against SQL injection. Network ACLs and Security Groups provide network-level security but do not inspect web traffic for specific attack patterns like SQL injection.

Spot Instances offer the lowest cost for Amazon EC2 and are suitable for non-production workloads like development and testing where occasional unavailability is acceptable. Spot Instances take advantage of unused EC2 capacity at a reduced cost, making them ideal for environments that can tolerate interruptions. Reserved or On-Demand Instances would be more expensive for this scenario, and Dedicated Hosts are not cost-effective for non-production environments.

 The benefit of the AWS Cloud that helps companies achieve lower usage costs because of the aggregate usage of all AWS users is economies of scale. Economies of scale means that AWS can achieve lower costs and higher efficiency by operating at a massive scale and passing the savings to the customers. AWS leverages the aggregate usage of all AWS users to negotiate better prices with hardware vendors, optimize power consumption, and improve operational processes. As a result, AWS can offer lower and more flexible pricing options to the customers, such as pay-as-you-go, reserved, and spot pricing models. No need to guess capacity, ability to go global in minutes, and increased speed and agility are other benefits of the AWS Cloud, but they are not directly related to the aggregate usage of all AWS users. No need to guess capacity means that AWS customers can avoid the risk of over-provisioning or under-provisioning resources, and scale up or down as needed. Ability to go global in minutes means that AWS customers can deploy their applications and data in multiple regions around the world, and deliver them to users with high performance and availability. Increased speed and agility means that AWS customers can quickly and easily provision and access AWS resources, and accelerate their innovation and time to market.

 The correct answer is B because AWS Cloud9 is an AWS service that enables users to run their existing custom, nonproduction workloads in the AWS Cloud quickly and cost-effectively. AWS Cloud9 is a cloud-based integrated development environment (IDE) that allows users to write, run, and debug code from a web browser. AWS Cloud9 supports multiple programming languages, such as Python, Java, Node.js, and more. AWS Cloud9 also provides users with a terminal that can access AWS services and resources, such as Amazon EC2 instances, AWS Lambda functions, and AWS CloudFormation stacks. The other options are incorrect because they are not AWS services that enable users to run their existing custom, nonproduction workloads in the AWS Cloud quickly and cost-effectively. AWS CodeBuild is an AWS service that enables users to compile, test, and package their code for deployment. AWS OpsWorks is an AWS service that enables users to configure and manage their applications using Chef or Puppet. AWS Cloud Development Kit (AWS CDK) is an AWS service that enables users to define and provision their cloud infrastructure using familiar programming languages, such as TypeScript, Python, Java, and C#. Reference: AWS Cloud9 FAQs

Amazon RDS supports six database engines: Amazon Aurora, MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server. Apache Cassandra, MongoDB, and Neo4j are not compatible with Amazon RDS. Therefore, the correct answer is D. You can learn more about Amazon RDS and its supported database engines

AWS WAF is the AWS service that the company should use to configure rules to identify threats and protect applications from malicious network access. AWS WAF is a web application firewall that helps to filter, monitor, and block malicious web requests based on customizable rules. AWS WAF can be integrated with other AWS services, such as Amazon CloudFront, Amazon API Gateway, and Application Load Balancer. For more information, see What is AWS WAF? and How AWS WAF Works.

The correct answer is B because placing the EC2 instances in two separate Availability Zones within the same AWS Region is the best way to meet the requirement. Availability Zones are isolated locations within an AWS Region that have independent power, cooling, and networking. Users can launch their resources, such as Amazon EC2 instances, in multiple Availability Zones to increase the fault tolerance and resilience of their applications. Availability Zones within the same AWS Region are connected with low-latency, high-throughput, and highly redundant networking. The other options are incorrect because they are not the best ways to meet the requirement. Placing the EC2 instances in two separate AWS Regions connected with a VPC peering connection is not the best way to meet the requirement because AWS Regions are geographically dispersed and may have higher communication latency between them than Availability Zones within the same AWS Region. VPC peering connection is a networking connection between two VPCs that enables users to route traffic between them using private IP addresses. Placing one EC2 instance on premises and the other in an AWS Region, and then connecting them by using an AWS VPN connection is not the best way to meet the requirement because on-premises and AWS Region are geographically dispersed and may have higher communication latency between them than Availability Zones within the same AWS Region. AWS VPN connection is a secure and encrypted connection between a user’s network and their VPC. Placing both EC2 instances in a placement group for dedicated bandwidth is not the best way to meet the requirement because a placement group is a logical grouping of instances within a single Availability Zone that enables users to launch instances with specific performance characteristics. A placement group does not ensure that the instances are in separate data centers, and it does not provide low-latency communication between instances in different AvailabilityZones. Reference: [Regions, Availability Zones, and Local Zones], [VPC Peering], [AWS VPN], [Placement Groups]

Some of the advantages of using Amazon EC2 instances to host applications in the AWS Cloud instead of on premises are:

EC2 integrates with Amazon VPC, AWS CloudTrail, and AWS Identity and Access Management (IAM). Amazon VPC lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network that you define. AWS CloudTrail enables governance, compliance, operational auditing, and risk auditing of your AWS account. AWS IAM enables you to manage access to AWS services and resources securely. Therefore, the correct answer is B. You can learn more about Amazon EC2 and its integration with other AWS services

EC2 has a flexible, pay-as-you-go pricing model. You only pay for the compute capacity you use, and you can scale up and down as needed. You can also choose from different pricing options, such as On-Demand, Savings Plans, Reserved Instances, and Spot Instances, to optimize your costs. Therefore, the correct answer is D. You can learn more about Amazon EC2 pricing

The other options are incorrect because:

EC2 does not include operating system patch management. You are responsible for managing and maintaining your own operating systems on EC2 instances. You can use AWS Systems Manager to automate common maintenance tasks, such as applying patches, or use Amazon EC2 Image Builder to create and maintain secure images. Therefore, the incorrect answer is A.

EC2 does not have a 100% service level agreement (SLA). The EC2 SLA guarantees 99.99% availability for each EC2 Region, not for each individual instance. Therefore, the incorrect answer is C.

EC2 does not have automatic storage cost optimization. You are responsible for choosing the right storage option for your EC2 instances, such as Amazon Elastic Block Store (EBS) or Amazon Elastic File System (EFS), and monitoring and optimizing your storage costs. You can use AWS Cost Explorer or AWS Trusted Advisor to analyze and reduce your storage spending. Therefore, the incorrect answer is E.

 The AWS service that the company should use for the data warehouse is Amazon Redshift. Amazon Redshift is a fully managed, petabyte-scale data warehouse service that is optimized for analytical queries. It can integrate with various data sources and business intelligence tools to provide fast and cost-effective insights. Amazon Redshift also offers high availability, scalability, security, and compliance features. [Amazon Redshift Overview]

The correct answer is C because Spot Instances are the pricing model that enables the company to run its existing custom, nonproduction workloads in the AWS Cloud quickly and cost-effectively. Spot Instances are spare Amazon EC2 instances that are available at up to 90% discount compared to On-Demand prices. Spot Instances are suitable for stateless, fault-tolerant, and flexible workloads that can recover from interruptions easily. The other options are incorrect because they are not the pricing model that enables the company to run its existing custom, nonproduction workloads in the AWS Cloud quickly and cost-effectively. Reserved Instances are Amazon EC2 instances that are reserved for a specific period of time (one or three years) in exchange for a lower hourly rate. Reserved Instances are suitable for steady-state or predictable workloads that run for a long duration. On-Demand Instances are Amazon EC2 instances that are launched and billed at a fixed hourly rate. On-Demand Instances are suitable for short-term, irregular, or unpredictable workloads that cannot be interrupted. Dedicated Hosts are physical servers that are dedicated to a single customer. Dedicated Hosts are suitable for workloads that require regulatory compliance or data isolation. Reference: Amazon EC2 Instance Purchasing Options

An Amazon Machine Image (AMI) is a deployable Amazon EC2 instance template that is prepackaged with software and security requirements. It provides the information required to launch an instance, which is a virtual server in the cloud. You can use an AMI to launch as many instances as you need. You can also create your own custom AMIs or use AMIs shared by other AWS users1.

 Global reach is the benefit of AWS Cloud computing that provides lower latency between users and applications. Global reach means that AWS customers can deploy their applications and data in multiple regions around the world, and deliver them to users with high performance and availability. AWS has the largest global infrastructure of any cloud provider, with 25 geographic regions and 81 Availability Zones, as well as 216 Points of Presence in 84 cities across 42 countries. Customers can choose the optimal locations for their applications and data based on their business requirements, such as compliance, data sovereignty, and customer proximity. Agility, economies of scale, and pay-as-you-go pricing are other benefits of AWS Cloud computing, but they do not directly provide lower latency between users and applications. Agility means that AWS customers can quickly and easily provision and scale up or down AWS resources as needed, without upfront costs or long-term commitments. Economies of scale means that AWS customers can benefit from the lower costs and higher efficiency that AWS achieves by operating at a massive scale and passing the savings to the customers. Pay-as-you-go pricing means that AWS customers only pay for the AWS resources they use, without any upfront costs or long-term contracts.

The AWS service that is used to temporarily provide federated security credentials to a user is AWS Security Token Service (AWS STS). AWS STS is a service that enables customers to request temporary, limited-privilege credentials for AWS Identity and Access Management (IAM) users or for users that they authenticate (federated users). The company can use AWS STS to grant federated users access to AWS resources without creating permanent IAM users or sharing long-term credentials. AWS STS helps customers manage and secure access to their AWS resources for federated users. Amazon GuardDuty, AWS Secrets Manager, and AWS Certificate Manager are not the best services to use for this purpose. Amazon GuardDuty is a threat detection service that monitors for malicious activity and unauthorized behavior across the AWS accounts and resources.AWS Secrets Manager is a service that helps customers manage and rotate secrets, such as database credentials, API keys, and passwords. AWS Certificate Manager is a service that helps customers provision, manage, and deploy public and private Secure Sockets Layer/Transport Layer Security (SSL/TLS) certificates for use with AWS services and internal connected resources. These services are more useful for different types of security and compliance tasks, rather than providing temporary federated security credentials to a user.

The AWS service that will meet the requirements of the company that is hosting a web application on Amazon EC2 instances and wants to implement custom conditions to filter and control inbound web traffic is AWS WAF. AWS WAF is a web application firewall that helps protect web applications from common web exploits that could affect availability, compromise security, or consume excessive resources. The company can use AWS WAF to create custom rules that block malicious requests that match certain patterns, such as SQL injection or cross-site scripting. AWS WAF can be applied to web applications that are behind an Application Load Balancer, Amazon CloudFront, or Amazon API Gateway. Amazon GuardDuty, Amazon Macie, and AWS Shield are not the best services to use for this purpose. Amazon GuardDuty is a threat detection service that monitors for malicious activity and unauthorized behavior across the AWS accounts and resources. Amazon Macie is a data security and data privacy service that uses machine learning and pattern matching to discover, classify, and protect sensitive data stored in Amazon S3. AWS Shield is a managed distributed denial of service (DDoS) protection service that safeguards web applications running on AWS. These services are more useful for detecting and preventing different types of threats and attacks, rather than filtering and controlling inbound web traffic based on custom conditions.

The advantages of moving to the AWS Cloud are the ability to use the pay-as-you-go model and no longer having to guess what capacity will be required. The pay-as-you-go model allows the user to pay only for the resources they use, without any upfront or long-term commitments. This reduces the cost and risk of over-provisioning or under-provisioning resources. No longer having to guess what capacity will be required means that the user can scale their resources up or down according to the demand, without wasting money on idle resources or losing customers due to insufficient capacity4.

The correct answer is B because Spot Instances enable the company to optimize costs and meet the requirements. Spot Instances are spare EC2 instances that are available at up to 90% discount compared to On-Demand prices. Spot Instances are suitable for stateless, fault-tolerant, and flexible applications that can run for any duration. The other options are incorrect because they do not enable the company to optimize costs and meet the requirements. Reserved Instances are EC2 instances that are reserved for a specific period of time (one or three years) in exchange for a lower hourly rate. Reserved Instances are suitable for steady-state or predictable workloads that run for a long duration. On-Demand Instances are EC2 instances that are launched and billed at a fixed hourly rate. On-Demand Instances are suitable for short-term, irregular, or unpredictable workloads that cannot be interrupted. Dedicated Instances are EC2 instances that run on hardware that is dedicated to a single customer. Dedicated Instances are suitable for workloads that require regulatory compliance or data isolation. Reference: [Amazon EC2 Instance Purchasing Options]

 The AWS service or tool that provides recommendations to help users get rightsized Amazon EC2 instances based on historical workload usage data is AWS Compute Optimizer. AWS Compute Optimizer is a service that analyzes the configuration and performance of the AWS resources, such as Amazon EC2 instances, and provides recommendations for optimal resource types and sizes based on the workload patterns and metrics. AWS Compute Optimizer helps users improve the performance, availability, and cost efficiency of their AWS resources. AWS Pricing Calculator, AWS App Runner, and AWS Systems Manager are not the best services or tools to use for this purpose. AWS Pricing Calculator is a tool that helps users estimate the cost of using AWS services based on their requirements and preferences. AWS App Runner is a service that helps users easily and quickly deploy web applications and APIs without managing any infrastructure. AWS Systems Manager is a service that helps users automate and manage the configuration and operation of their AWS resources and applications34