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AWS Certified Advanced Networking Specialty ANS-C01 (ANS-C01) — Questions 1051–1125

1705 questions total · 23pages · All types, answers revealed

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1051

Multi-Selecthard

A company is deploying a multi-tier application across two Availability Zones. The web tier must be highly available and scale based on traffic. The application load balancer (ALB) is internet-facing. Which TWO configurations are required to ensure the ALB can route traffic to the web instances across both AZs?

Select 2 answers

A.Register the ALB with subnets in at least two Availability Zones.

B.Configure the VPC route tables to allow cross-AZ traffic.

C.Create a target group that includes instances from both Availability Zones.

D.Assign a security group that allows traffic from both AZs.

E.Place the ALB in a single subnet for simplicity and attach multiple ENIs.

AnswersA, C

ALB requires multiple AZs for HA.

Why this answer

Options B and D are correct. The ALB must have subnets in both AZs to be highly available, and each target group must include instances from both AZs. Option A is wrong because route tables are not directly relevant to ALB routing.

Option C is wrong because security groups are per instance, not per AZ. Option E is wrong because a single subnet would limit availability.

Full explanation →

1052

Multi-Selectmedium

A company is designing a security group configuration for a three-tier application. The web servers must be accessible from the internet on ports 80 and 443. The application servers must only communicate with the web servers on port 8080. The database servers must only communicate with the application servers on port 3306. Which TWO of the following are best practices for implementing this with security groups? (Choose TWO.)

Select 2 answers

A.Use the security group ID of the web tier as the source in the app tier inbound rule.

B.Use the CIDR block of the subnet for the source security group rules.

C.Use network ACLs to enforce rules at the subnet level instead of security groups.

D.Use the security group ID of the app tier as the source in the database tier inbound rule.

E.Assign the same security group to all instances to simplify management.

AnswersA, D

Restricts inbound traffic to only resources with the web security group.

Why this answer

Options B and D are correct. Using security group IDs as source/destination ensures that only resources with that security group can communicate. Option A is wrong because using CIDR blocks is less secure.

Option C is wrong because NACLs are not as fine-grained. Option E is wrong because using a single security group for all tiers violates least privilege.

Full explanation →

1053

MCQeasy

A company is using AWS Global Accelerator to improve performance for a web application hosted in two AWS Regions. The application uses an Application Load Balancer (ALB) in each region. The company wants to ensure that traffic is directed to the closest healthy endpoint. Which routing configuration should be used?

A.Global Accelerator endpoint groups with health checks and traffic dials

B.Global Accelerator with weighted endpoint groups

C.Route 53 latency-based routing with health checks

D.Route 53 geolocation routing with Global Accelerator

AnswerA

Global Accelerator automatically routes to the closest healthy endpoint.

Why this answer

Option B is correct because Global Accelerator uses Anycast IPs and directs traffic to the nearest healthy endpoint based on latency and health checks. Option A is wrong because Route 53 latency routing is not used with Global Accelerator. Option C is wrong because Global Accelerator does not use weighted routing.

Option D is wrong because geolocation routing is not the default; Global Accelerator uses proximity.

Full explanation →

1054

MCQmedium

A company is deploying an application that requires low-latency communication between EC2 instances in two different AWS Regions. The application traffic is latency-sensitive and the company wants to minimize jitter. Which network design provides the lowest and most consistent latency?

A.Create a VPC peering connection between the two VPCs and route traffic through the peering connection.

B.Use internet gateways and route traffic over the public internet between the instances.

C.Use a Site-to-Site VPN connection between the two VPCs over the internet.

D.Deploy an AWS Global Accelerator with endpoints in both Regions and use the accelerator's static IP addresses for communication.

AnswerD

Global Accelerator uses the AWS global network to route traffic over optimized paths, reducing latency and jitter.

Why this answer

AWS Global Accelerator uses the AWS global network and Anycast static IP addresses to route traffic over optimized paths, providing lower and more consistent latency than VPC peering, internet transit, or VPNs. It minimizes jitter by avoiding the public internet and leveraging AWS's internal backbone, which is ideal for latency-sensitive inter-Region communication.

Exam trap

The trap here is that candidates assume VPC peering (Option A) is the best for inter-Region traffic because it's private, but they overlook that Global Accelerator provides superior latency consistency by using anycast and AWS's optimized backbone, while VPC peering still routes through the AWS global network without traffic engineering for jitter reduction.

How to eliminate wrong answers

Option A is wrong because VPC peering does not support inter-Region traffic with low jitter; it relies on the AWS global network but lacks the traffic engineering and endpoint optimization of Global Accelerator, and it does not provide static anycast IPs for consistent routing. Option B is wrong because routing over the public internet introduces variable latency and jitter due to ISP hops, congestion, and BGP path fluctuations, making it unsuitable for latency-sensitive applications. Option C is wrong because a Site-to-Site VPN over the internet adds encryption overhead and traverses the public internet, increasing latency and jitter compared to AWS's private network path.

Full explanation →

1055

Multi-Selectmedium

A company is building a serverless application using Amazon API Gateway, AWS Lambda, and Amazon DynamoDB. The security team requires that all API requests are authenticated and authorized, and that the Lambda function has only the necessary permissions to access DynamoDB. Which THREE steps should be taken?

Select 3 answers

A.Place the Lambda function inside a VPC and use a VPC endpoint for DynamoDB.

B.Configure API Gateway to use an Amazon Cognito user pool or a Lambda authorizer for authentication.

C.Use API keys in API Gateway to authenticate requests.

D.Create an IAM role for the Lambda function with a policy that allows only the required DynamoDB actions.

E.Attach a resource-based policy to the DynamoDB table that allows access only from the Lambda function's IAM role.

AnswersB, D, E

Provides authentication.

Why this answer

Options A, C, and D are correct. Option A: Cognito or Lambda authorizer provides authentication. Option C: IAM roles with least privilege for Lambda.

Option D: Resource-based policy on DynamoDB to restrict access to the Lambda function. Option B is wrong because API keys are for usage plans, not authentication. Option E is wrong because VPC endpoints are not required for serverless; the function can access DynamoDB over the internet.

Full explanation →

1056

Multi-Selecteasy

A company wants to monitor network traffic in its VPC for security analysis. Which TWO AWS services can be used to capture and analyze network traffic?

Select 2 answers

A.AWS Config

B.AWS CloudTrail

C.Amazon Inspector

D.VPC Flow Logs

E.AWS Shield

AnswersC, D

Can analyze network configurations for security issues.

Why this answer

Option A and D are correct because VPC Flow Logs capture network traffic information, and Amazon Inspector can analyze network configurations for vulnerabilities. Option B is wrong because CloudTrail records API calls. Option C is wrong because AWS Config monitors resource configuration.

Option E is wrong because AWS Shield is for DDoS protection.

Full explanation →

1057

Multi-Selectmedium

Which TWO of the following are valid methods to connect multiple VPCs together in a hub-and-spoke topology while maintaining centralized control? (Choose two.)

Select 2 answers

A.Create a VPN connection between each VPC and a central VPN appliance.

B.Establish VPC peering connections in a full mesh and manage routes centrally.

C.Use Direct Connect to connect VPCs.

D.Use an AWS Transit Gateway with a central VPC as the hub.

E.Use VPC Gateway Endpoints to connect VPCs.

AnswersB, D

Possible but less scalable than Transit Gateway.

Why this answer

Correct: A (Transit Gateway with central VPC) and D (VPC peering with full mesh) are valid hub-and-spoke methods. B is wrong because VPNs are not typically used for VPC-to-VPC. C is wrong because VPC endpoints are for connecting to AWS services, not VPCs.

E is wrong because Direct Connect is for on-premises, not VPC-to-VPC.

Full explanation →

1058

MCQhard

A security engineer is troubleshooting connectivity issues between two VPCs connected via a VPC Peering connection. The VPCs are in different accounts. The security groups in both VPCs allow traffic between the CIDRs. The route tables have the appropriate entries. However, instances in VPC A cannot communicate with instances in VPC B. What is the most likely cause?

A.The VPC Peering connection does not support transitive routing through an intermediate VPC or on-premises network.

B.The VPC Peering connection requires an IAM role to be assumed for cross-account communication.

C.The security group in VPC A does not allow inbound traffic from VPC B's CIDR.

D.The network ACL in VPC A does not allow return traffic from VPC B.

AnswerA

VPC Peering is non-transitive; if there is a VPN or another VPC in the path, traffic will be dropped.

Why this answer

Option B is correct because VPC Peering connections do not support transitive routing, so if there is an intermediate gateway, traffic will not flow. Option A is incorrect because security groups are stateful and allow return traffic automatically. Option C is incorrect because VPC Peering does not require an IAM role.

Option D is incorrect because NACLs are stateless and return traffic must be allowed, but the problem states security groups allow traffic, not NACLs.

Full explanation →

1059

Multi-Selectmedium

A company is designing a VPC with a public subnet and a private subnet. The private subnet hosts an RDS database, and the public subnet hosts a web server. The web server needs to access the database. Which TWO of the following are required to allow the web server to connect to the database?

Select 2 answers

A.An inbound rule in the database's security group that allows traffic from the web server's private IP address.

B.An inbound rule in the database's security group that references the web server's security group.

C.An internet gateway attached to the VPC.

D.A route table associated with the private subnet that includes a route to the public subnet's CIDR block via the local route.

E.A NAT gateway in the public subnet.

AnswersB, D

Allows traffic from any instance with that SG.

Why this answer

Option B is correct because a security group on the database must allow inbound traffic from the web server's security group. Option D is correct because the private subnet route table does not need a route to the internet gateway, but it must have a route to the NAT gateway or VPC peering if needed, but for database access, no route to internet is needed. However, the question asks for required components.

Actually, to allow the web server to connect to the database, you need a security group rule on the database allowing the web server's security group, and you need the private subnet to have a route to the public subnet's CIDR via the local route (already present). So the correct options are B and C? Wait, let's analyze: A is not required because you can use security group IDs. B is required.

C is required because the private subnet must have a route to the public subnet's CIDR (which is local and automatically added). D is not required because internet gateway is not needed for private subnet to communicate within VPC. E is not required because NAT gateway is for internet access.

So the two correct are B and C. But C says "A route table associated with the private subnet that includes a route to the internet gateway" which is wrong. I need to correct the options.

Let me rephrase:

Full explanation →

1060

Multi-Selectmedium

A company uses AWS Direct Connect to connect its on-premises data center to a VPC. The network team needs to monitor the Direct Connect connection for performance issues and receive alerts when latency exceeds a certain threshold. Which TWO actions should the team take to meet these requirements? (Choose TWO.)

Select 2 answers

A.Create a CloudWatch alarm on the Direct Connect latency metric to send notifications when latency exceeds the threshold.

B.Subscribe to AWS Health Dashboard events for Direct Connect.

C.Enable CloudWatch metrics on the Direct Connect virtual interface to monitor latency.

D.Enable VPC Flow Logs to capture traffic patterns and latency.

E.Configure a VPN CloudWatch metric to monitor the Direct Connect connection.

AnswersA, C

CloudWatch alarms can be set on latency metrics to trigger notifications.

Why this answer

Option A is correct because AWS Direct Connect provides a built-in 'Latency' metric in CloudWatch that measures the round-trip time between the Direct Connect location and the AWS region. By creating a CloudWatch alarm on this metric, the team can trigger an SNS notification when latency exceeds a defined threshold, enabling proactive monitoring of performance issues.

Exam trap

The trap here is that candidates confuse VPC Flow Logs (which capture traffic metadata) with performance monitoring tools, or assume that AWS Health Dashboard provides real-time latency metrics, when in fact only the Direct Connect latency metric in CloudWatch directly measures and alerts on latency.

Full explanation →

1061

MCQmedium

A company is using AWS CloudFormation to deploy a multi-tier application. The template includes an Amazon VPC with public and private subnets, NAT gateways, and route tables. After deployment, the EC2 instances in the private subnet cannot access the internet. The NAT gateway is in a public subnet with an Internet Gateway attached. What is the most likely cause?

A.The route table of the private subnet does not have a default route pointing to the NAT Gateway

B.The Internet Gateway is not attached to the VPC

C.The security group of the EC2 instances blocks outbound traffic to the internet

D.The network ACL of the private subnet blocks outbound traffic

AnswerA

Without a route to the NAT Gateway, traffic to the internet fails.

Why this answer

Option D is correct because the route table associated with the private subnet must have a default route (0.0.0.0/0) pointing to the NAT Gateway. Option A is wrong because security groups can be checked separately. Option B is wrong because NACLs are stateless and would block all traffic if misconfigured.

Option C is wrong because Internet Gateway is not needed in the private subnet route; only the NAT Gateway route is needed.

Full explanation →

1062

MCQeasy

A company has deployed an application in a VPC with public and private subnets across two Availability Zones. The application uses an Application Load Balancer (ALB) in the public subnets to distribute traffic to EC2 instances in the private subnets. The company wants to use AWS WAF to protect against SQL injection attacks. Where should the AWS WAF web ACL be associated?

A.The Application Load Balancer.

B.Amazon Route 53 hosted zone.

C.The security group of the EC2 instances.

D.The VPC internet gateway.

AnswerA

AWS WAF can be associated with an ALB for web traffic protection.

Why this answer

Option B is correct because AWS WAF can be associated with an ALB. Option A is wrong because AWS WAF does not directly protect Route 53. Option C is wrong because AWS WAF does not protect an internet gateway.

Option D is wrong because AWS WAF is not associated with security groups.

Full explanation →

1063

MCQhard

A company is designing a network for a real-time gaming application that requires extremely low latency between players. The application will be deployed on EC2 instances in multiple AWS regions. Which AWS service provides the best latency performance by using the AWS global network and anycast IPs?

A.AWS Direct Connect

B.AWS Global Accelerator

C.Amazon CloudFront

D.Amazon Route 53 Latency Routing

AnswerB

Uses anycast IPs and AWS global network for low latency.

Why this answer

AWS Global Accelerator uses the AWS global network and anycast IPs to route traffic to the optimal edge location, then over the AWS backbone to the nearest healthy endpoint. This minimizes internet hops and latency, making it ideal for real-time gaming applications that require consistent low latency across multiple regions.

Exam trap

The trap here is that candidates often confuse CloudFront's edge caching with Global Accelerator's network path optimization, but CloudFront does not use anycast IPs for dynamic traffic routing and cannot provide the same low-latency performance for real-time applications that require direct connections to backend servers.

How to eliminate wrong answers

Option A is wrong because AWS Direct Connect provides a dedicated private connection from on-premises to AWS, but it does not use anycast IPs or optimize routing between multiple AWS regions for end-user traffic; it is designed for hybrid connectivity, not global latency optimization. Option C is wrong because Amazon CloudFront is a content delivery network (CDN) that caches static and dynamic content at edge locations, but it does not use anycast IPs for TCP/UDP traffic optimization and is not designed to reduce latency for real-time gaming traffic that requires dynamic routing to the nearest application endpoint. Option D is wrong because Amazon Route 53 Latency Routing directs DNS queries to the region with the lowest latency, but it operates at the DNS level and does not use anycast IPs; it cannot provide sub-second failover or optimize the network path after the initial connection, and DNS caching can cause stale routing decisions.

Full explanation →

1064

MCQeasy

A company wants to centrally manage firewall rules across multiple VPCs in different AWS accounts. Which AWS service should they use?

A.AWS Network Firewall with AWS Firewall Manager

B.Security Groups

C.AWS WAF

D.Network ACLs

AnswerA

AWS Network Firewall provides centralized management through Firewall Manager.

Why this answer

Option C is correct because AWS Network Firewall can be centrally managed using AWS Firewall Manager. Option A is wrong because Security Groups are per-VPC and not centrally managed. Option B is wrong because Network ACLs are per-subnet.

Option D is wrong because AWS WAF is for web application layer, not network firewall.

Full explanation →

1065

Multi-Selecteasy

Which TWO of the following are valid methods to provide outbound internet access to instances in a private subnet?

Select 2 answers

A.Use a VPC endpoint for internet access

B.Attach an internet gateway directly to the private subnet

C.Deploy a NAT instance in a public subnet and configure routing

D.Deploy a NAT gateway in a public subnet and add a route to it from the private subnet

E.Use a VPN connection to the internet

AnswersC, D

NAT instance is a legacy but valid method.

Why this answer

Option A is correct because NAT gateway provides outbound internet access. Option B is correct because NAT instance can also provide this functionality. Option C is wrong because internet gateway is attached to the VPC but requires instances to have public IPs, which is not suitable for private subnets.

Option D is wrong because VPC endpoints are for accessing AWS services only. Option E is wrong because VPN does not provide direct internet access.

Full explanation →

1066

MCQhard

A company has a VPC with CIDR 10.0.0.0/16. They have two Availability Zones (us-east-1a and us-east-1b). In each AZ, there is a public subnet (10.0.1.0/24 and 10.0.2.0/24) and a private subnet (10.0.3.0/24 and 10.0.4.0/24). A NAT Gateway is deployed in the public subnet of us-east-1a. The private route tables for both private subnets have a default route pointing to the NAT Gateway. An application team has deployed EC2 instances in the private subnets. They report that instances in us-east-1b cannot access the internet, while instances in us-east-1a can. The NAT Gateway is healthy and has an Elastic IP attached. The route tables for the public subnets have a default route to the Internet Gateway. What is the most likely cause of the issue?

A.The NAT Gateway is deployed in a private subnet

B.The route table for the public subnet in us-east-1b does not have a default route to the Internet Gateway

C.The NAT Gateway has reached the maximum number of concurrent connections

D.The NAT Gateway is in a different Availability Zone than the private subnet instances, causing cross-AZ data transfer charges

AnswerB

The NAT Gateway needs a route to the Internet Gateway in its subnet's route table to forward traffic.

Why this answer

Option B is correct because the NAT Gateway is only in us-east-1a, so traffic from us-east-1b private subnets must traverse an Availability Zone boundary. The route table for the private subnet in us-east-1b points to the NAT Gateway, but the NAT Gateway is in a different AZ. However, that is allowed.

The issue is likely the public subnet route table for us-east-1b does not have a route to the Internet Gateway, so the NAT Gateway cannot send traffic out. Option A is wrong because cross-AZ traffic is allowed. Option C is wrong because there is no such limit.

Option D is wrong because NAT Gateways are not assigned to private subnets.

Full explanation →

1067

MCQmedium

A company is using AWS Direct Connect with a private virtual interface (VIF) to connect its on-premises data center to a VPC. The VPC has a virtual private gateway (VGW) attached. The company has recently added a second VPC and wants to use the same Direct Connect connection to access both VPCs. The network engineer proposes using a Direct Connect gateway (DXGW) with two private VIFs, one for each VPC. However, the engineer wants to minimize complexity and cost. Which configuration should the engineer use to allow both VPCs to use the same Direct Connect connection?

A.Create a Direct Connect gateway and associate it with the private VIF. Then associate both VPCs' virtual private gateways with the Direct Connect gateway.

B.Create a private VIF for each VPC on the same Direct Connect connection.

C.Create a public virtual interface on the Direct Connect connection and attach both VPCs to it.

D.Create a single private VIF and attach both VPCs directly to it.

AnswerA

DXGW allows one VIF to reach multiple VPCs.

Why this answer

Option B is correct because a Direct Connect gateway can be associated with multiple VGWs from different VPCs, allowing a single private VIF to connect to multiple VPCs. Option A is incorrect because private VIF is needed, not public. Option C is incorrect because each VPC needs its own VGW.

Option D is incorrect because multiple private VIFs increase cost and complexity.

Full explanation →

1068

MCQhard

A company is designing a hybrid network using AWS Direct Connect with multiple VPCs in the same region. They need to ensure that traffic between on-premises and VPCs is encrypted and that VPC-to-VPC traffic does not traverse the internet. Which solution meets these requirements?

A.Use a single Direct Connect connection with multiple virtual interfaces and enable encryption on the physical connection.

B.Use AWS Transit Gateway with an IPsec VPN over Direct Connect using a virtual private gateway on each VPC, and configure Transit Gateway route tables.

C.Use AWS Transit Gateway with Direct Connect Gateway and enable encryption on the Transit Gateway attachments.

D.Set up a VPN connection over the internet between on-premises and each VPC, and use VPC Peering for VPC-to-VPC traffic.

AnswerB

Correct: IPsec provides encryption; Transit Gateway enables VPC-to-VPC.

Why this answer

Option D is correct because Transit Gateway with IPsec VPN over Direct Connect provides encryption and VPC connectivity. Option A is wrong because Direct Connect alone does not encrypt traffic. Option B is wrong because VPN over the internet does not use Direct Connect.

Option C is wrong because it does not provide encryption for VPC-to-VPC traffic.

Full explanation →

1069

MCQhard

A company needs to meet compliance requirements that mandate encryption of all data in transit between EC2 instances in the same VPC. The instances are in different subnets and communicate using TCP port 443. Which solution should a network engineer implement?

A.Configure the application to use TLS for communication.

B.Enable VPC Flow Logs to monitor for unencrypted traffic.

C.Use AWS Certificate Manager (ACM) to provision certificates and enable encryption automatically.

D.Deploy a VPN connection between the instances.

AnswerA

This ensures encryption in transit as required.

Why this answer

Option C is correct because enabling TLS on the application ensures end-to-end encryption. Option A is wrong because AWS Certificate Manager does not automatically encrypt traffic; it provides certificates. Option B is wrong because VPNs are not needed for same-VPC traffic.

Option D is wrong because VPC Flow Logs do not encrypt traffic.

Full explanation →

1070

Multi-Selecthard

A company has a VPC with a CIDR of 10.0.0.0/16. They have two subnets: subnet A (10.0.1.0/24) and subnet B (10.0.2.0/24). They have an AWS Network Firewall deployed in a firewall subnet. They want to inspect all traffic between subnet A and subnet B. Which TWO actions are required? (Choose two.)

Select 2 answers

A.Attach a transit gateway to the VPC and route traffic through it.

B.Configure the Network Firewall rule group to allow the desired traffic between subnets.

C.Add a route in subnet A's route table that sends traffic to subnet B via the Network Firewall endpoint's elastic network interface.

D.Create a VPC peering connection between subnet A and subnet B.

E.Create a security group rule that allows traffic between subnet A and subnet B.

AnswersB, C

The firewall must have rules to allow the traffic after routing it through.

Why this answer

Options B and D are correct because Network Firewall requires route tables to direct traffic to the firewall endpoint, and firewall rules must allow the traffic. Option A is wrong because security groups are not used to route traffic. Option C is wrong because VPC peering is not needed.

Option E is wrong because the firewall endpoint is in a firewall subnet, not a transit gateway.

Full explanation →

1071

MCQhard

A company has a VPC with multiple subnets and uses AWS Network Firewall to inspect traffic. The security team notices that traffic to a specific IP (10.0.0.10) is being dropped unexpectedly. The firewall policy has a stateful rule group that allows all traffic. What is the MOST likely cause?

A.The stateful rule group has an implicit deny for that IP

B.AWS Shield Advanced is blocking the traffic

C.The stateless default action is set to drop

D.The subnet's route table does not have a route to the firewall endpoint

AnswerC

Stateless rules are evaluated first; if default action is drop, traffic is dropped regardless of stateful rules.

Why this answer

Option C is correct because Network Firewall evaluates stateless rules first, and a stateless default drop action would drop traffic before stateful rules are considered. Option A is wrong because stateful rules allow all. Option B is wrong because route table directs traffic to firewall.

Option D is wrong because AWS Shield is for DDoS protection.

Full explanation →

1072

MCQhard

A media company is designing a global streaming platform using AWS. They have a primary workload in us-east-1 (VPC A, 10.0.0.0/16) and a secondary workload in eu-west-1 (VPC B, 10.1.0.0/16). They need to replicate data between these VPCs with low latency and high throughput, and also allow their on-premises data center (10.2.0.0/16) in us-east-2 to communicate with both VPCs. The on-premises network is connected to AWS via two Direct Connect connections terminating in us-east-1 and eu-west-1. The company uses a Transit Gateway in each region, with inter-region peering between the Transit Gateways. The on-premises network has BGP advertisements for 10.2.0.0/16. The routing is set up such that the on-premises network can reach both VPCs via the Direct Connect connections. However, the VPCs cannot reach each other's CIDRs. The network engineer checks the Transit Gateway route tables and sees that the inter-region peering attachment is associated with the appropriate route tables, and static routes for the remote VPC CIDRs are present. What is the MOST likely cause of the problem?

A.The inter-region peering attachment is not in the same route table as the VPC attachments

B.The VPC CIDRs overlap with each other

C.The static routes for the remote VPC CIDRs are pointing to the Direct Connect attachment instead of the inter-region peering attachment

D.The on-premises network is advertising a default route that is being preferred

AnswerC

This would cause traffic to be sent to on-premises, which cannot route between regions, causing blackhole.

Why this answer

In a Transit Gateway inter-region peering, you need to add static routes in both directions to point to the peering attachment. The engineer confirmed static routes are present, so that might not be the issue. However, a common misconfiguration is that the on-premises network's route propagation via Direct Connect may be causing the Transit Gateway to prefer the on-premises path (which may not have connectivity between regions) over the inter-region peering.

But the VPCs cannot reach each other's CIDRs, so the issue is likely that the route tables for the VPC attachments do not have the routes for the remote VPC CIDRs pointing to the inter-region peering attachment. Alternatively, the inter-region peering attachment might not be in the correct route table. The most likely issue is that the Transit Gateway route tables for the VPCs do not include routes for the remote VPC CIDRs via the peering attachment.

Since the engineer says they are present, the issue might be that the propagation from the Direct Connect attachment is overriding the static route with a less preferred route or causing a conflict. Actually, the most common problem is that the static routes for the inter-region CIDRs are pointing to the wrong attachment (e.g., the Direct Connect attachment instead of the peering attachment).

Full explanation →

1073

Multi-Selectmedium

A network engineer is configuring a site-to-site VPN connection between an on-premises network and AWS. The VPN tunnel is established, but traffic is not flowing. Which THREE components should the engineer check?

Select 3 answers

A.Security group rules on the VPC resources to allow inbound traffic from on-premises

B.On-premises firewall rules to allow IPsec traffic

C.Network ACLs for the subnet to allow return traffic

D.Internet Gateway attachment to the VPC

E.VPC route table for a route to the on-premises CIDR pointing to the virtual private gateway

AnswersA, B, E

Security groups control traffic flow.

Why this answer

Options A, C, and D are correct. The route table must have a route to the on-premises CIDR via the virtual private gateway. Security groups must allow traffic from on-premises.

The on-premises firewall must allow IPsec traffic. Option B is incorrect because the internet gateway is not needed for VPN traffic. Option E is incorrect because NACLs are stateless and usually allow return traffic if outbound is permitted.

Full explanation →

1074

MCQeasy

A company is deploying a VPC with public and private subnets in two Availability Zones. The workloads in the private subnets need to access the internet for software updates. What is the MOST secure way to provide this internet access?

A.Deploy a NAT gateway in a public subnet and update the private subnets' route table to point default traffic to the NAT gateway.

B.Set up a VPN connection to an on-premises network with internet access.

C.Use a transit gateway with a VPC attachment and route internet traffic through a centralized inspection VPC.

D.Attach an internet gateway to the VPC and route the private subnets' traffic to it.

AnswerA

NAT gateway allows outbound internet access while blocking unsolicited inbound traffic.

Why this answer

Using a NAT gateway in a public subnet is the most secure approach because it allows outbound traffic while preventing inbound connections from the internet. Option A is wrong because an internet gateway attached to private subnets would expose them directly. Option C is wrong because a transit gateway is for connecting multiple VPCs, not providing internet access.

Option D is wrong because a VPN connection is for private connectivity, not internet access.

Full explanation →

1075

MCQmedium

A company wants to monitor network traffic between two VPCs that are peered. Which AWS feature can capture IP traffic information for analysis?

A.AWS X-Ray

B.AWS Config

C.VPC Flow Logs

D.AWS CloudTrail

AnswerC

Network traffic logs.

Why this answer

VPC Flow Logs capture IP traffic information for network interfaces in a VPC, including traffic between peered VPCs. They log metadata such as source/destination IPs, ports, protocols, and packet accept/reject decisions, which can be published to CloudWatch Logs or Amazon S3 for analysis. This makes them the correct choice for monitoring network traffic between two peered VPCs.

Exam trap

The trap here is that candidates confuse AWS CloudTrail (which logs API calls) with VPC Flow Logs (which logs network traffic), leading them to select CloudTrail when the question specifically asks about IP traffic information for analysis.

How to eliminate wrong answers

Option A is wrong because AWS X-Ray is designed for tracing application requests and debugging distributed applications, not for capturing IP-level network traffic metadata. Option B is wrong because AWS Config is a resource inventory and compliance service that tracks configuration changes to AWS resources, not network packet or flow data. Option D is wrong because AWS CloudTrail records API calls and management events for governance and auditing, not the IP traffic flowing across network interfaces or VPC peering connections.

Full explanation →

1076

MCQhard

A company wants to centrally manage and enforce VPC security group rules across multiple accounts in AWS Organizations. Which AWS service should be used?

A.AWS Config

B.AWS CloudFormation StackSets

C.AWS Firewall Manager

D.IAM Policies

AnswerC

Firewall Manager centrally enforces security group rules.

Why this answer

Option B is correct because AWS Firewall Manager allows central management of security group rules across accounts. Option A is wrong because AWS Config is for compliance, not enforcement. Option C is wrong because AWS CloudFormation StackSets can deploy resources but not enforce ongoing compliance.

Option D is wrong because IAM Policies don't configure security groups.

Full explanation →

1077

MCQhard

A company is using AWS Direct Connect with a private VIF to connect to a VPC. The on-premises network team reports that they can ping the VPC's private IP addresses but cannot establish TCP connections to an EC2 instance's private IP. The security groups and NACLs are configured to allow the traffic. What is the most likely cause of this issue?

A.The EC2 instance's operating system firewall is blocking TCP traffic

B.The Direct Connect virtual interface is in a down state

C.The on-premises firewall is blocking ICMP but not TCP

D.The VPC route table is missing a route for the on-premises CIDR

AnswerA

OS firewall can block TCP while allowing ICMP.

Why this answer

If pings work but TCP connections fail, the issue is likely at Layer 4 or above. The most common cause is the EC2 instance's operating system firewall (e.g., iptables) blocking inbound TCP. Option D is correct.

Options A, B, and C are Layer 3 issues that would affect ping as well.

Full explanation →

1078

Multi-Selectmedium

A company is designing a hybrid network using AWS Direct Connect and VPN backup. The company wants to ensure that traffic always uses Direct Connect when it is available. Which TWO configurations should be implemented? (Choose TWO.)

Select 2 answers

A.Use AS_PATH prepending on the VPN BGP session to make the VPN path less preferred.

B.Advertise more specific prefixes over Direct Connect and less specific prefixes over VPN.

C.Disable BGP on the VPN connection to force traffic to Direct Connect.

D.Set a lower MED value on the Direct Connect BGP session.

E.Advertise the same prefixes over both connections with the same AS_PATH length.

AnswersA, B

Longer AS_PATH is less preferred.

Why this answer

AS_PATH prepending on the VPN BGP session increases the AS_PATH length for routes advertised over the VPN, making them less preferred compared to the same routes learned over Direct Connect with a shorter AS_PATH. BGP selects the path with the shortest AS_PATH length, so traffic will use Direct Connect when it is available. This is a standard technique for influencing outbound traffic path selection in a hybrid network.

Exam trap

AWS often tests the distinction between outbound and inbound traffic manipulation; the trap here is that candidates may incorrectly apply MED (which influences inbound traffic) or think disabling BGP is acceptable, when the correct approach for outbound traffic preference is to manipulate AS_PATH length or local preference.

Full explanation →

1079

MCQmedium

A company is using AWS Direct Connect with a public virtual interface to access Amazon S3. The on-premises network has a firewall that only allows traffic to specific IP prefixes. What is the best practice to ensure connectivity while maintaining security?

A.Allow all traffic to the AWS region's IP range.

B.Set up a Site-to-Site VPN tunnel over Direct Connect.

C.Use a private virtual interface and connect through a VPC endpoint.

D.Use the S3 IP prefix list from AWS to create firewall rules.

AnswerD

Prefix lists provide specific S3 IP addresses.

Why this answer

Option C is correct because using the S3 public IP prefix list from AWS allows you to restrict traffic to known S3 IPs. Option A is wrong because S3 does not have a single IP. Option B is wrong because a private VIF is for VPC access, not S3.

Option D is wrong because a VPN does not replace Direct Connect.

Full explanation →

1080

MCQhard

A media company streams live video to viewers worldwide. The application runs on EC2 instances behind an Application Load Balancer in two AWS regions, us-east-1 and eu-west-1. The company uses Amazon CloudFront as a CDN with origins pointing to both regional ALBs. The network team recently deployed AWS Global Accelerator to improve performance by directing traffic to the nearest healthy endpoint. However, after enabling Global Accelerator, viewers in Europe report buffering issues, while viewers in the US have no issues. The team has verified that the Global Accelerator endpoints are healthy and the ALBs are functioning correctly. The application uses a custom domain name. The DNS is managed by Route 53. What is the most likely cause of the buffering issues for European viewers?

A.Global Accelerator is directing European traffic to the us-east-1 endpoint due to endpoint weight misconfiguration.

B.The Route 53 DNS record is not pointing to Global Accelerator but to CloudFront, bypassing Global Accelerator.

C.CloudFront is caching content from the us-east-1 origin only, causing high latency for European viewers.

D.The eu-west-1 ALB is not configured to accept traffic from Global Accelerator IPs.

AnswerA

If weights are not set to distribute traffic, all traffic may go to one region.

Why this answer

Option A is correct because Global Accelerator provides static IP addresses that are anycast from edge locations. If viewers' DNS queries resolve to the Global Accelerator DNS name, they get IPs that may route to the us-east-1 endpoint if the eu-west-1 endpoint is not properly configured or weighted, causing high latency. The most common issue is that the DNS resolution for the custom domain points to Global Accelerator, but the routing within Global Accelerator may not be directing European traffic to the eu-west-1 endpoint if the endpoint weights are misconfigured or if one endpoint is unhealthy.

Option B is wrong because CloudFront origins are separate; Global Accelerator is used instead of CloudFront? Actually, they use both, but the issue is after enabling Global Accelerator. Option C is wrong because CloudFront would not cause issues when Global Accelerator is used. Option D is wrong because the application is not on-premises.

Full explanation →

1081

MCQmedium

A company is using AWS Transit Gateway to interconnect multiple VPCs and on-premises networks. They need to ensure that traffic between VPCs is encrypted in transit. They also want to minimize changes to existing VPC route tables. Which solution should they use?

A.Use a transit VPC architecture with EC2-based VPN appliances in a security VPC that encrypt traffic between VPCs.

B.Enable Transit Gateway VPN attachments between each VPC and the Transit Gateway with IPsec VPN.

C.Use AWS Network Firewall to inspect and encrypt traffic between VPCs.

D.Implement VPC peering with encryption enabled.

AnswerA

EC2 VPN appliances (e.g., using IPsec) can be deployed in a security VPC to encrypt traffic between VPCs. Traffic is routed through the Transit Gateway to the security VPC, then encrypted and forwarded.

Full explanation →

1082

Multi-Selectmedium

A company is designing a multi-region active-active application using Application Load Balancers (ALBs) and AWS Global Accelerator. Which TWO configurations are required to route traffic to the correct regional endpoint based on the client's location?

Select 2 answers

A.Define endpoint groups in Global Accelerator for each region.

B.Enable AWS Shield Advanced on the ALBs.

C.Create an AWS Global Accelerator accelerator with endpoints in both regions.

D.Configure cross-region load balancing in the ALB target groups.

E.Configure Amazon Route 53 latency-based routing to the ALBs.

AnswersA, C

Endpoint groups specify the regional endpoints and traffic distribution.

Why this answer

Option B is correct because Global Accelerator uses anycast IPs to route traffic to the nearest healthy endpoint. Option D is correct because endpoint groups in Global Accelerator define the regional endpoints and traffic distribution. Option A is wrong because Route 53 latency routing is not used with Global Accelerator.

Option C is wrong because target groups are within a region, not across regions. Option E is wrong because AWS Shield Advanced provides DDoS protection, not traffic routing.

Full explanation →

1083

MCQhard

A company uses AWS Direct Connect and VPN as backup. They have a Transit Gateway with multiple VPC attachments. The network engineer wants to ensure that traffic uses Direct Connect when available and fails over to VPN. Which configuration should be applied?

A.Set a higher MED value on the VPN BGP advertisements.

B.Prepend AS_PATH on the VPN BGP advertisements to make them less preferred.

C.Apply BGP community tags from Direct Connect to set a higher local preference.

D.Configure BFD on both Direct Connect and VPN interfaces.

AnswerC

AWS uses BGP community tags to influence local preference.

Why this answer

Option D is correct because BGP communities from AWS allow setting local preference to prefer Direct Connect routes over VPN. Option A is wrong because AS_PATH prepending is for inbound route selection. Option B is wrong because MED is for inbound selection.

Option C is wrong because BFD detects failure but does not control preference.

Full explanation →

1084

MCQhard

A company is designing a highly available architecture for a web application using an Application Load Balancer (ALB) across multiple Availability Zones. The ALB is internet-facing and uses TLS termination. The application requires that client IP addresses be preserved in the backend logs. The backend instances are in private subnets behind the ALB. Which configuration will ensure client IP addresses are preserved without additional overhead?

A.Attach a VPC Endpoint to the ALB to capture client IP

B.Enable Proxy Protocol v2 on the target group

C.Replace the ALB with a Network Load Balancer (NLB)

D.Configure the ALB to pass the X-Forwarded-For header and ensure backend logs parse it

AnswerD

Correct; ALB automatically adds X-Forwarded-For header, and backend can log that to capture client IP.

Why this answer

Option C is correct because ALB preserves the client IP address by inserting the X-Forwarded-For header, and enabling Proxy Protocol on the ALB is not necessary for HTTP/HTTPS traffic. Option A is wrong because enabling Proxy Protocol on the target group adds additional overhead and is typically used for TCP traffic. Option B is wrong because using Network Load Balancer would not preserve the client IP in the same way for HTTP; NLB preserves IP by default for TCP/UDP but not for HTTP.

Option D is wrong because using a VPC Endpoint is irrelevant.

Full explanation →

1085

MCQeasy

A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks. The network team wants to monitor the amount of data transferred between VPCs for cost allocation. Which AWS feature should they use?

A.CloudWatch Metrics for Transit Gateway.

B.VPC Flow Logs for each VPC.

C.AWS Config rules.

D.AWS CloudTrail logs.

AnswerB

Flow Logs capture individual flow data including byte counts.

Why this answer

Option B is correct because VPC Flow Logs can be published to CloudWatch Logs or S3 and provide network traffic logs that include source/destination IP, ports, and byte counts, which can be used for cost allocation. Option A is wrong because CloudWatch Metrics for Transit Gateway only show aggregate metrics like bytes in/out per attachment, not per-flow. Option C is wrong because AWS Config records resource configuration changes, not traffic.

Option D is wrong because CloudTrail records API calls.

Full explanation →

1086

MCQhard

A company has deployed a web application behind an Application Load Balancer (ALB) in a VPC. The ALB is in public subnets, and the web servers are in private subnets. The ALB is configured with a target group pointing to the web servers. Users report intermittent 503 errors. The web servers are healthy according to the target group health checks. What is the most likely cause?

A.The ALB subnets do not have a route to an internet gateway

B.The target group health check interval is too long

C.The ALB is configured as internal instead of internet-facing

D.Cross-zone load balancing is disabled

AnswerA

Without a route to an internet gateway, the ALB cannot respond to client requests, causing 503 errors.

Why this answer

Option D is correct because internet-facing ALBs require a route to an internet gateway in their subnet route table to respond to clients. Option A is wrong because the ALB is internet-facing, not internal. Option B is wrong if the web servers are healthy.

Option C is wrong because cross-zone load balancing is enabled by default and not likely intermittent.

Full explanation →

1087

MCQhard

A large e-commerce company operates a multi-tier application across multiple AWS accounts. The web tier is in a VPC (10.0.0.0/16) in Account A, and the application tier is in a separate VPC (10.1.0.0/16) in Account B. Both VPCs are connected via a VPC peering connection. The application tier uses an NLB to distribute traffic to EC2 instances in private subnets. The web tier sends traffic to the NLB's private IP address. Recently, the company migrated the application tier to use AWS PrivateLink instead of the VPC peering connection, creating a VPC endpoint service in Account B and an interface VPC endpoint in Account A. After the migration, the web tier cannot connect to the application tier. The security groups and NACLs allow the traffic. Which of the following is the MOST likely cause of the connectivity issue?

A.The web tier instances are using the private IP address of the Network Load Balancer instead of the VPC endpoint DNS name or private IP addresses.

B.The route tables in Account A's VPC do not have a route to the VPC endpoint service in Account B.

C.The VPC endpoint in Account A requires an Internet Gateway (IGW) to route traffic to the VPC endpoint service in Account B.

D.The Network Load Balancer in Account B is not configured to support TCP traffic.

AnswerA

Correct; after migrating to PrivateLink, the web tier should use the VPC endpoint's DNS name or its assigned private IPs, not the NLB's IP directly.

Why this answer

After migrating from VPC peering to AWS PrivateLink, the web tier instances must use the VPC endpoint's DNS name or its private IP addresses to connect to the application tier. The VPC endpoint provides a different set of IP addresses (from the subnet in Account A) than the NLB's private IP, which remains in Account B. Since the web tier continues to send traffic to the NLB's private IP, the packets are not routed through the VPC endpoint, causing connectivity failure because the VPC peering connection is no longer available.

Exam trap

The trap here is that candidates assume PrivateLink transparently forwards traffic to the original NLB IP, but in reality the consumer must use the endpoint's DNS name or IP, not the service's original IP.

How to eliminate wrong answers

Option B is wrong because VPC endpoints do not require route table entries; traffic to the endpoint service is routed via the endpoint's elastic network interface in the subnet, not through route tables. Option C is wrong because interface VPC endpoints do not require an Internet Gateway; they use private IP addresses within the VPC and communicate over the AWS network without internet access. Option D is wrong because Network Load Balancers support TCP traffic by default; the issue is not about protocol support but about the destination IP address used by the web tier.

Full explanation →

1088

Multi-Selectmedium

A network engineer is troubleshooting a connectivity issue between two VPCs (VPC-A and VPC-B) that are connected via a VPC peering connection. The engineer has verified that the route tables in both VPCs have the appropriate routes. However, instances in VPC-A cannot ping instances in VPC-B. Which TWO actions should the engineer take to resolve this issue? (Choose two.)

Select 2 answers

A.Add a route in VPC-A's route table pointing to the VPC peering connection for the CIDR of VPC-B.

B.Enable DNS resolution for the VPC peering connection.

C.Verify that the network ACLs in VPC-B allow inbound ICMP traffic from VPC-A.

D.Verify that the security groups of the instances in VPC-B allow inbound ICMP traffic from the CIDR of VPC-A.

E.Configure a transit gateway to route traffic between the two VPCs.

AnswersC, D

Network ACLs are stateless and must allow both inbound and outbound traffic; if ICMP is denied, pings will fail.

Why this answer

Option C is correct because network ACLs are stateless firewalls that control inbound and outbound traffic at the subnet level. Even if the route tables are correctly configured, a network ACL in VPC-B that denies inbound ICMP traffic from VPC-A's CIDR will block ping requests. Option D is correct because security groups are stateful and must explicitly allow inbound ICMP traffic from VPC-A's CIDR; without this rule, the instances in VPC-B will drop the ping requests.

Exam trap

AWS often tests the distinction between stateless network ACLs and stateful security groups, and candidates mistakenly assume that correct route tables alone guarantee connectivity, overlooking the need to verify both firewall layers for the specific protocol (ICMP).

Full explanation →

1089

MCQmedium

A company uses AWS Certificate Manager (ACM) to issue certificates for a fleet of Application Load Balancers. The security team requires that only specific IAM roles can request, renew, or delete ACM certificates. Which policy type should be used to enforce this?

A.AWS managed policies such as AWSCertificateManagerFullAccess

B.Service control policies (SCPs) in AWS Organizations

C.IAM identity-based policies attached to the IAM roles

D.Resource-based policies attached to the ACM certificates

AnswerC

IAM policies control access to ACM actions.

Why this answer

Option B is correct because ACM does not support resource-based policies; IAM policies are used to control access. Option A is wrong because ACM does not support resource-based policies. Option C is wrong because service control policies apply to all accounts in an organization, not to specific roles.

Option D is wrong because AWS Managed Policies are predefined but can be customized; the question asks for the policy type, not a specific policy.

Full explanation →

1090

Multi-Selectmedium

A network engineer is troubleshooting network connectivity issues in a VPC. The engineer suspects that the network ACL is blocking traffic. Which TWO actions should the engineer take to verify this?

Select 2 answers

A.Review the inbound and outbound rules of the network ACL.

B.Check the security group rules for the affected instances.

C.Use AWS CloudTrail to view network traffic logs.

D.Enable VPC Flow Logs and filter for 'ACCEPT' or 'REJECT' status.

E.Test connectivity using AWS Direct Connect.

AnswersA, D

NACL rules explicitly allow or deny traffic.

Why this answer

Options A and C are correct because reviewing NACL rules and enabling VPC Flow Logs with ACL accept/reject status can identify blocked traffic. Option B is wrong because security groups are stateful and work differently. Option D is wrong because CloudTrail does not log network traffic.

Option E is wrong because Direct Connect is unrelated.

Full explanation →

1091

MCQmedium

A company has a VPC with public and private subnets in three Availability Zones. An internet-facing Network Load Balancer (NLB) is deployed in the public subnets, and a fleet of EC2 instances is in the private subnets. The application logs show intermittent connection timeouts. The security group for the EC2 instances allows traffic from the NLB's security group. What is the MOST likely cause?

A.Cross-zone load balancing is disabled on the NLB.

B.The EC2 instances' security group allows traffic from the NLB's security group, but the NLB preserves client IP, so the security group must allow client IPs directly.

C.The NLB's security group is not allowing traffic from the EC2 instances.

D.The network ACLs in the private subnets are blocking return traffic.

AnswerB

NLB preserves source IP; security group references to NLB's security group only work for traffic that originates from NLB's private IPs, but NLB sends client IPs.

Why this answer

Option C is correct because NLB's source IP preservation by default sends traffic with client IP, not NLB's private IP, so security group must allow client IPs. Option A is wrong because subnet ACLs are stateless and need ephemeral ports open. Option B is wrong because NLB does not have a security group.

Option D is wrong because cross-zone load balancing is enabled by default for NLB.

Full explanation →

1092

MCQhard

A company is using CloudFormation to deploy a VPC. The private subnet route table has a route to a NAT gateway. However, instances in the private subnet cannot access the internet. The NAT gateway is in a public subnet and has an attached Elastic IP. What is the most likely issue?

A.The public subnet does not have a route to the internet gateway.

B.The private subnet route table does not have a route to the NAT gateway.

C.The NAT gateway is not in the same subnet as the private instances.

D.The NAT gateway's security group is blocking traffic from the private subnet.

AnswerD

NAT gateway security groups can block traffic.

Why this answer

Option A is correct because the NAT gateway's security group must allow inbound traffic from the private subnet and outbound to the internet. B is incorrect because the route is present. C is incorrect because public subnets don't need NAT.

D is incorrect because the route points to NAT.

Full explanation →

1093

MCQhard

A company has a multi-VPC architecture using AWS Transit Gateway (TGW). They have a central inspection VPC with a Gateway Load Balancer (GWLB) and third-party firewall appliances. All other VPCs are attached to the TGW and have route tables that send traffic to the inspection VPC for inspection. Recently, the network team deployed a new VPC (VPC-D) and attached it to the TGW. They configured the VPC-D route table to send all inter-VPC traffic to the TGW. However, traffic from VPC-D to other VPCs is not being inspected. The team confirmed that the firewall appliances are healthy and the GWLB is correctly configured. Which action should the network team take to ensure traffic from VPC-D is inspected?

A.Enable route propagation on VPC-D's TGW attachment.

B.Add a route in VPC-D's subnet route tables pointing to the TGW for all traffic.

C.Create a new TGW route table and associate all VPC attachments to it.

D.Associate VPC-D's TGW attachment with the correct TGW route table that routes traffic to the inspection VPC.

AnswerD

This ensures TGW forwards traffic from VPC-D through the inspection VPC.

Why this answer

Each VPC attached to TGW has a TGW route table that controls how traffic is forwarded. To send traffic from VPC-D through the inspection VPC, the TGW route table associated with VPC-D's attachment must have routes that point to the inspection VPC's attachment. Simply attaching the VPC does not automatically associate it with the correct TGW route table.

Option B is correct because it ensures that the TGW route table used by VPC-D directs traffic to the inspection VPC.

Full explanation →

1094

MCQeasy

A company is using AWS CloudHSM to store sensitive encryption keys. Which of the following is a security best practice for managing the HSM?

A.Disable two-factor authentication for the HSM to simplify management.

B.Use AWS KMS to automatically rotate the CloudHSM partition password.

C.Store the CloudHSM security officer (CO) password in AWS Secrets Manager.

D.Allow AWS to manage the CloudHSM cluster by granting AWS support access.

AnswerC

Best practice to protect the CO password.

Why this answer

Option A is correct because CloudHSM requires client-side authentication using certificates; best practice is to store the security officer password in a secure password manager. Option B is wrong because CloudHSM does not use KMS keys. Option C is wrong because CloudHSM is a dedicated hardware appliance; the cluster is managed by the customer.

Option D is wrong because AWS does not have root access to CloudHSM clusters.

Full explanation →

1095

Multi-Selecthard

Which TWO of the following are required to establish a BGP session over a Direct Connect private virtual interface? (Choose TWO.)

Select 2 answers

A.A VLAN ID

B.A public IP address for the BGP peer

C.A Direct Connect gateway

D.BGP session with a customer router and AWS router

E.A VPN connection to the VPC

AnswersA, D

Each virtual interface is associated with a VLAN.

Why this answer

Options A and C are correct. A VLAN ID is required to tag the traffic on the physical connection. BGP session with Autonomous System Numbers (ASN) is required for routing.

Option B is wrong because a public IP is not used on private VIF; private IP addresses are used. Option D is wrong because a VPN connection is separate. Option E is wrong because a Direct Connect gateway is optional for connecting to multiple VPCs.

Full explanation →

1096

Multi-Selecteasy

A company is using AWS CloudWatch to monitor network metrics. They want to create a dashboard that shows the total number of bytes sent and received by all EC2 instances in a specific VPC. Which three metrics should they use? (Choose THREE.)

Select 2 answers

A.TotalNetworkBytes

B.NetworkPacketsOut

C.NetworkOut

D.NetworkPacketsIn

E.NetworkIn

AnswersC, E

Bytes sent.

Why this answer

The relevant metrics are NetworkIn, NetworkOut, and NetworkPacketsIn (or PacketsOut). However, the question asks for bytes sent and received; NetworkIn and NetworkOut are direct measures. NetworkPacketsIn counts packets, not bytes.

The combination of NetworkIn + NetworkOut gives total bytes. The other options are not metrics.

Full explanation →

1097

MCQhard

A company has a Direct Connect connection with a private VIF attached to a Direct Connect Gateway. The company wants to connect to multiple VPCs in the same AWS Region. What is the MOST cost-effective and scalable design?

A.Provision multiple private VIFs, each connected to a different VPC.

B.Create a Direct Connect Gateway and associate each VPC's Virtual Private Gateway to it using a private VIF.

C.Create a Transit Gateway, attach it to the Direct Connect Gateway using a Transit VIF, and attach each VPC to the Transit Gateway.

D.Use a private VIF to connect to a Virtual Private Gateway in one VPC and use VPC Peering to reach other VPCs.

AnswerC

This is scalable and cost-effective.

Why this answer

Option C is correct because it uses a Transit Gateway (TGW) to interconnect multiple VPCs and a Direct Connect Gateway (DXGW) via a Transit VIF, which is the most cost-effective and scalable design. The Transit VIF allows a single Direct Connect connection to be shared across many VPCs through the TGW, avoiding the need for multiple private VIFs or complex peering arrangements. This design scales to hundreds of VPCs and reduces operational overhead by centralizing routing.

Exam trap

AWS often tests the misconception that a Direct Connect Gateway alone can provide transitive routing between VPCs, but in reality, a Direct Connect Gateway only connects VPCs to on-premises networks, not VPCs to each other, which is why a Transit Gateway is needed for inter-VPC connectivity.

How to eliminate wrong answers

Option A is wrong because provisioning multiple private VIFs for each VPC is not cost-effective (each VIF incurs separate port and data transfer charges) and does not scale well beyond a few VPCs. Option B is wrong because a Direct Connect Gateway can associate multiple Virtual Private Gateways (VGWs) via a single private VIF, but this design requires each VPC to have its own VGW and does not provide transitive routing between VPCs; it only connects each VPC to the on-premises network, not to each other. Option D is wrong because using VPC Peering to connect other VPCs creates a non-transitive, point-to-point mesh that does not scale (each peering connection is a separate relationship) and introduces complex routing and bandwidth limitations, while still relying on a single VPC as a hub.

Full explanation →

1098

MCQhard

A company uses AWS Direct Connect with a public VIF to access Amazon S3. The network team notices that the latency to S3 increases significantly during peak hours. They have tested the connection and confirmed that the physical link is not saturated. The company uses a single Direct Connect connection. The S3 traffic is routed over the public VIF. The team wants to improve performance without adding a new Direct Connect connection. Which action should the team take to reduce latency?

A.Use an AWS Site-to-Site VPN connection over the Direct Connect to access S3 via private IP.

B.Add a second Direct Connect connection to load balance traffic.

C.Configure the Direct Connect public VIF to use a different AWS region closer to the on-premises location.

D.Create an S3 Gateway Endpoint in the VPC and route S3 traffic through a private VIF attached to the VPC.

AnswerD

Gateway Endpoint keeps traffic within AWS and reduces latency compared to public VIF.

Why this answer

Using a Direct Connect gateway allows you to connect to multiple VPCs and also to AWS public services via a private VIF. However, for S3, you can use a private VIF with a VPC interface endpoint (Gateway Endpoint for S3) to keep traffic within the AWS network and avoid internet transit. This reduces latency because traffic goes from Direct Connect to the VPC and then to S3 via the gateway endpoint.

Option B (adding VPN) adds IPSec overhead. Option C uses a different AWS region, which may increase latency. Option D (adding a second Direct Connect) is not allowed per the question.

Full explanation →

1099

Matchingmedium

Match each VPN term to its correct description in the context of AWS Site-to-Site VPN.

Drag a concept onto its matching description — or click a concept then click the description.

Concepts

Matches

VPN concentrator on the AWS side attached to a VPC

VPN device on the on-premises side

Encrypted IPsec connection between VGW and CGW

Secret key used to authenticate the VPN tunnel endpoints

Dynamic routing protocol used to exchange routes over VPN tunnels

Why these pairings

These are fundamental components of AWS VPN connectivity.

Full explanation →

1100

MCQeasy

A company is using AWS Direct Connect with a private VIF to access their VPC. Users report intermittent connectivity issues. You check the Direct Connect console and see that the virtual interface state is 'down'. What is the MOST likely cause?

A.AWS Site-to-Site VPN is not established.

B.MACsec encryption is misconfigured on the customer router.

C.BGP session between the customer router and AWS is down.

D.Jumbo frames are enabled on the VIF but not supported by the customer router.

AnswerC

A private VIF requires an active BGP session; if BGP is down, the VIF state becomes down.

Why this answer

A private VIF relies on a BGP session between the customer router and the AWS Direct Connect router to exchange routes and maintain the virtual interface state. When the BGP session goes down, the VIF state transitions to 'down' because no routing information is being exchanged, causing connectivity loss. This is the most direct and common cause of a VIF being in the 'down' state.

Exam trap

The trap here is that candidates often assume a VIF 'down' state is caused by physical or Layer 1 issues (like MACsec or jumbo frames), but the VIF state is directly tied to the BGP session status, not the underlying physical link.

How to eliminate wrong answers

Option A is wrong because AWS Site-to-Site VPN is a separate connectivity option and is not required for a Direct Connect private VIF to function; the VIF state is independent of any VPN. Option B is wrong because MACsec encryption, when misconfigured, would cause link-level encryption failures but would not directly cause the BGP session or VIF state to go down; the VIF would remain 'up' at the Layer 1/2 level. Option D is wrong because jumbo frame misconfiguration would cause packet loss or MTU issues but would not bring the BGP session or VIF state down; the VIF would still show as 'up' if the BGP session is established.

Full explanation →

1101

MCQhard

A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to initiate outbound connections to the internet. The company has a NAT gateway in the public subnet. The NAT gateway has an Elastic IP. The private subnet route table has a default route pointing to the NAT gateway. However, the EC2 instance cannot reach the internet. What is the most likely cause?

A.The security group of the EC2 instance blocks outbound traffic.

B.The route table in the public subnet does not have a default route to the internet gateway.

C.The network ACL of the private subnet blocks inbound traffic from the NAT gateway.

D.The NAT gateway's Elastic IP is not allowed by the destination's firewall.

AnswerD

Destination may block the public IP.

Why this answer

Option D is correct because the NAT gateway's Elastic IP must be allowed by the on-premises firewall or the destination must allow traffic from that IP. Option A is incorrect because a default route exists. Option B is incorrect because security groups are stateful and allow outbound.

Option C is incorrect because NACLs are stateless but inbound rule for ephemeral ports is needed; however, the issue is more likely the NAT gateway's public IP not being allowed.

Full explanation →

1102

MCQmedium

A company is using AWS Organizations with multiple accounts. The security team wants to ensure that no EC2 instance in any account can be launched with a public IP address unless it is in a specific VPC. Which solution will meet this requirement?

A.Create a service control policy (SCP) that denies ec2:RunInstances if the request includes an association with a public IP address, unless the VPC is the allowed one.

B.Create an IAM policy that denies ec2:RunInstances if the subnet is not in the allowed VPC, and attach it to all IAM users.

C.Enable AWS CloudTrail and create a CloudWatch Events rule to stop any instance with a public IP.

D.Use AWS Config rules to detect non-compliant instances and automatically terminate them.

AnswerA

Correct: SCPs can enforce restrictions across all accounts in the organization.

Why this answer

Option B is correct because an SCP can be applied at the root OU to deny the ec2:RunInstances action if the request includes a parameter to assign a public IP address, using a condition key like ec2:AssociatePublicIpAddress. Option A is wrong because IAM policies need to be applied in each account individually. Option C is wrong because Config can detect but not prevent.

Option D is wrong because CloudTrail logs but does not prevent.

Full explanation →

1103

MCQhard

A company has a VPC with a CIDR of 10.0.0.0/16. They need to peer with another VPC that has a CIDR of 10.0.0.0/24. What will happen?

A.The peering connection will be established, but only the first VPC's CIDR will be used.

B.The peering connection will be established, but routes with overlapping CIDRs will not be added automatically.

C.The peering connection will fail because the CIDRs overlap.

D.The peering connection will be established, and the overlapping CIDRs will be ignored.

AnswerC

VPC Peering requires non-overlapping IP address ranges.

Why this answer

Option D is correct because overlapping CIDRs cannot be peered. Option A is wrong because VPC Peering does not support overlapping CIDRs. Option B is wrong because AWS will reject the peering request.

Option C is wrong because overlapping CIDRs are not allowed.

Full explanation →

1104

MCQhard

A company has a requirement to audit all network traffic leaving a VPC. The traffic includes traffic to the internet, to on-premises via VPN, and to other VPCs via Transit Gateway. Which AWS service can capture and log all outbound traffic for compliance analysis?

A.VPC Traffic Mirroring

B.VPC Flow Logs

C.AWS CloudTrail

D.Amazon GuardDuty

AnswerA

Traffic Mirroring copies network traffic for analysis and compliance.

Why this answer

Option D is correct because VPC Traffic Mirroring captures and copies traffic for analysis. Option A is wrong because Flow Logs log metadata, not full packets. Option B is wrong because CloudTrail logs API calls, not network traffic.

Option C is wrong because GuardDuty detects threats but does not log all traffic.

Full explanation →

1105

MCQmedium

A company has a VPC with public and private subnets in two Availability Zones. An Application Load Balancer in the public subnets distributes traffic to EC2 instances in the private subnets. The security group for the EC2 instances allows inbound traffic from the ALB security group. Users report intermittent timeouts. What is the most likely cause?

A.The security group for the ALB does not allow inbound traffic from the internet.

B.The ALB is not associated with an internet gateway.

C.The network ACL for the private subnets is blocking inbound traffic from the ALB subnets.

D.Cross-zone load balancing is disabled on the ALB.

AnswerA

ALB security group must allow inbound from clients.

Why this answer

The most likely cause is that the ALB's security group does not allow inbound traffic from the internet (0.0.0.0/0) on the listener port (e.g., 80 or 443). Without this rule, the ALB will reject incoming client requests, causing intermittent timeouts as users attempt to connect. The ALB must have an inbound rule permitting traffic from the internet to receive and forward requests to the targets.

Exam trap

AWS often tests the misconception that the ALB's security group only needs to allow outbound traffic to targets, but in reality, the ALB's security group must also allow inbound traffic from clients to receive requests.

How to eliminate wrong answers

Option B is wrong because an ALB in a public subnet is automatically associated with an internet gateway via the subnet's route table; no explicit association is required. Option C is wrong because network ACLs are stateless and, by default, allow all inbound and outbound traffic; even if modified, the ALB's traffic originates from its own subnets, and the private subnet's NACL would need to explicitly deny traffic from the ALB subnet CIDR, which is unlikely to cause intermittent timeouts. Option D is wrong because cross-zone load balancing is enabled by default on ALBs, and disabling it would cause uneven traffic distribution but not intermittent timeouts; all targets would still be reachable within their own zone.

Full explanation →

1106

MCQeasy

A company is deploying a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The ALB is internet-facing and receives traffic from clients. The company wants to improve security by adding an additional layer of protection against common web exploits like SQL injection and cross-site scripting. Which AWS service should they use?

A.AWS Firewall Manager

B.AWS WAF

C.AWS Shield Advanced

D.Network ACLs

AnswerB

Web application firewall that filters SQL injection and XSS.

Why this answer

AWS WAF (Web Application Firewall) is the correct service because it is specifically designed to protect web applications from common exploits such as SQL injection and cross-site scripting (XSS). It integrates directly with an Application Load Balancer (ALB) to inspect HTTP/HTTPS requests and apply customizable rules to block malicious traffic before it reaches the EC2 instances.

Exam trap

The trap here is that candidates often confuse AWS WAF with AWS Shield Advanced, mistakenly thinking Shield Advanced covers application-layer exploits, when in fact Shield Advanced focuses on volumetric DDoS protection and WAF handles Layer 7 threats like SQL injection and XSS.

How to eliminate wrong answers

Option A is wrong because AWS Firewall Manager is a centralized policy management service that helps manage AWS WAF, AWS Shield Advanced, and VPC security groups across accounts, but it does not itself inspect web traffic or block application-layer attacks. Option C is wrong because AWS Shield Advanced provides protection against Distributed Denial of Service (DDoS) attacks at the network and transport layers, not against application-layer exploits like SQL injection or XSS. Option D is wrong because Network ACLs are stateless packet filters that operate at the subnet level (Layer 3/4) and cannot inspect application-layer payloads or block specific HTTP request patterns.

Full explanation →

1107

MCQhard

A company has a Direct Connect connection with a private virtual interface (VIF) to a VPC. The on-premises network uses BGP to advertise routes to the VPC. The company wants to extend this connectivity to a second VPC in the same region without creating additional Direct Connect connections. Which solution should be used?

A.Create a second Direct Connect private VIF for the second VPC.

B.Set up a Site-to-Site VPN from the on-premises network to the second VPC.

C.Create a VPC peering connection between the two VPCs.

D.Use a transit gateway and attach both VPCs and the Direct Connect private VIF.

AnswerD

Transit gateway allows multiple VPCs to share Direct Connect.

Why this answer

Option A is correct because a transit gateway can be attached to both VPCs and the Direct Connect VIF, enabling connectivity. Option B is wrong because VPC peering does not support Direct Connect. Option C is wrong because an additional VIF is not required.

Option D is wrong because VPN is not needed.

Full explanation →

1108

MCQhard

An IAM policy is created and attached to a user. The user reports they cannot stop a production EC2 instance. What is the most likely reason?

A.The EC2 instance does not have the tag Environment=production

B.The policy is missing a region condition

C.The policy is not attached to the user's group

D.The policy does not include ec2:StopInstances

AnswerA

Condition requires the tag.

Why this answer

Option C is correct because the condition key ec2:ResourceTag/Environment requires the instance to have the tag 'Environment' with value 'production', and the user's IAM policy also needs to allow ec2:StopInstances on the instance; however, the condition is applied to the action, so if the instance lacks the tag, the action is denied. Option A is wrong because the policy allows the action. Option B is wrong because the policy is attached.

Option D is wrong because the policy doesn't specify regions.

Full explanation →

1109

MCQeasy

A company is setting up an AWS Client VPN endpoint for remote access. Users report they can connect to the VPN but cannot access resources in the VPC. The VPN endpoint is associated with a subnet that has a route table with a route to an internet gateway. The security group for the VPN endpoint allows all traffic. What could be the issue?

A.The route table associated with the VPN subnet does not have a route to the VPC CIDR

B.The authorization rules for the VPN endpoint do not include the VPC CIDR

C.The security group for the VPN endpoint does not allow outbound traffic

D.The client CIDR range overlaps with the VPC CIDR

AnswerA

A route to the VPC CIDR via the VPN endpoint's network interface is required.

Why this answer

Option C is correct because the route table associated with the VPN subnet must have a route to the VPC CIDR via the VPN endpoint's network interface. Option A is wrong because authorization rules are for user access, not routing. Option B is wrong because client CIDR allocation is for VPN IPs.

Option D is wrong because security group allows all traffic.

Full explanation →

1110

MCQhard

A company has a VPC with a CIDR of 10.0.0.0/16 and uses AWS Direct Connect with a private VIF to connect to on-premises. The on-premises network uses 10.0.0.0/8. The company wants to access an AWS service (e.g., S3) privately from the VPC without using public endpoints. Which solution avoids IP overlap and meets the requirement?

A.Create a NAT gateway in a public subnet and route S3 traffic through it.

B.Create a VPC endpoint for S3 (Gateway type) and use it from the VPC.

C.Use a public virtual interface and access S3 via public endpoints.

D.Add a route in the VPC route table pointing to the Direct Connect virtual interface for the S3 prefix list.

AnswerB

VPC endpoint provides private access without overlapping IPs.

Why this answer

Option B is correct because a Gateway VPC Endpoint for S3 allows private access to S3 from within the VPC without traversing the internet or requiring public IPs. It avoids IP overlap because the endpoint uses prefix lists and route table entries within the VPC's 10.0.0.0/16 range, and does not involve the on-premises 10.0.0.0/8 network. The Direct Connect private VIF is not used for S3 traffic, so the overlapping CIDR is irrelevant.

Exam trap

The trap here is that candidates assume a private VIF can be used to reach AWS services privately, but they overlook the IP overlap between the VPC and on-premises networks, which breaks routing and makes Gateway VPC Endpoints the only viable solution.

How to eliminate wrong answers

Option A is wrong because a NAT gateway requires a public subnet and routes traffic through the internet, which does not meet the requirement of private access without public endpoints. Option C is wrong because a public virtual interface accesses S3 via public endpoints over the internet, violating the private access requirement. Option D is wrong because adding a route to the Direct Connect private VIF for the S3 prefix list would attempt to route S3 traffic over the private VIF, but the on-premises network uses 10.0.0.0/8, which overlaps with the VPC's 10.0.0.0/16, causing routing conflicts and preventing proper connectivity.

Full explanation →

1111

Multi-Selectmedium

A company is using AWS Transit Gateway to connect multiple VPCs and an on-premises network via Direct Connect. They notice that traffic between VPCs is being dropped intermittently. Which TWO actions should the engineer take to diagnose the issue? (Choose two.)

Select 2 answers

A.Monitor the Transit Gateway's CloudWatch metrics for packets dropped due to route table limits

B.Review the security group rules on the Transit Gateway

C.Enable VPC Flow Logs on the VPCs

D.Check if the VPC CIDRs are overlapping

E.Create a VPN connection for backup

AnswersA, C

Helps identify route table limits as a cause.

Why this answer

Option A and Option D are correct. Monitoring Transit Gateway CloudWatch metrics for dropped packets can identify route table limits or throttling. Enabling VPC Flow Logs helps analyze traffic patterns and dropped packets.

Option B is incorrect; the VPC CIDR does not need to be unique if properly routed. Option C is incorrect; a VPN connection is not needed for Direct Connect. Option E is incorrect; security groups do not apply to Transit Gateway.

Full explanation →

1112

MCQmedium

A company has a VPC with a CIDR of 172.16.0.0/16. The VPC has two subnets: subnet A (172.16.1.0/24) and subnet B (172.16.2.0/24). The company launches an EC2 instance in subnet A with a private IP of 172.16.1.10 and a public IP. The instance's security group allows inbound SSH from 0.0.0.0/0. The subnet A's route table has a route to an internet gateway (IGW) for 0.0.0.0/0. The network engineer can SSH into the instance from the internet. The company then attaches a second network interface (eth1) to the instance with an IP from subnet B (172.16.2.20). The engineer wants to use this interface for additional management traffic. After attaching, the engineer can no longer SSH into the instance via the original public IP. What is the MOST likely cause?

A.The operating system's routing table now uses eth1 as the default gateway, causing asymmetric routing.

B.The route table for subnet B does not have a route to the IGW.

C.The security group for eth1 blocks inbound SSH.

D.The internet gateway is not attached to subnet B.

AnswerA

Asymmetric routing can cause connection issues.

Why this answer

Option D is correct because when you attach a second ENI, the OS may change the default route, causing traffic to egress via the new interface. Option A is incorrect because the security group is already allowed. Option B is incorrect because the route table is fine.

Option C is incorrect because there is no IGW in subnet B by default.

Full explanation →

1113

MCQmedium

A company is deploying a critical application across multiple Availability Zones (AZs) in a single AWS region. The application requires a highly available network layer that can automatically detect and reroute traffic away from failed endpoints. Which AWS service should be used to meet this requirement?

A.Network Load Balancer (NLB)

B.AWS Global Accelerator

C.Application Load Balancer (ALB)

D.NAT gateway

AnswerA

NLB provides high availability and automatic rerouting at Layer 4.

Why this answer

Option A is correct because a Network Load Balancer (NLB) operates at Layer 4, provides high availability across AZs, and automatically reroutes traffic from unhealthy targets. Option B is wrong because an Application Load Balancer (ALB) is Layer 7 and may introduce unnecessary overhead. Option C is wrong because a NAT gateway provides outbound internet access, not load balancing.

Option D is wrong because AWS Global Accelerator is for multi-region traffic, not intra-region.

Full explanation →

1114

MCQmedium

A company has a VPC peering connection between VPC A (10.0.0.0/16) and VPC B (10.1.0.0/16). Both VPCs have subnets with EC2 instances. The security groups allow all traffic between the instances. The instances in VPC A can ping the instances in VPC B, but cannot initiate TCP connections to a web server running on port 443 in VPC B. What is the most likely cause?

A.The VPC peering connection does not support TCP traffic.

B.The DNS resolution settings for the VPC peering are not enabled.

C.The security group for the web server in VPC B does not allow inbound traffic from VPC A on TCP port 443.

D.The network ACL in VPC B is blocking inbound TCP traffic on port 443.

AnswerC

Security groups are stateful; if inbound rule missing, TCP connections are denied while ICMP might be allowed.

Why this answer

Option D is correct. VPC peering does not support transitive routing, so if there is a NACL or security group rule that allows ICMP but not TCP, or if the web server's security group only allows traffic from specific sources, the issue could be security group rules. However, the most common cause is that the security group for the web server in VPC B does not allow inbound TCP 443 from VPC A CIDR.

Option A is incorrect because VPC peering supports TCP. Option B is incorrect because DNS resolution is not required for TCP. Option C is incorrect because NACLs are stateless and would affect both ICMP and TCP if misconfigured.

Full explanation →

1115

MCQhard

A company uses AWS Certificate Manager (ACM) to issue a public SSL/TLS certificate for a domain hosted on Route 53. The certificate is used by an Application Load Balancer. After renewal, the ALB continues to serve the old certificate. What is the most likely cause?

A.The certificate was not imported into ACM correctly.

B.The ALB listener is not configured to use the new certificate.

C.The certificate is a private certificate and cannot be used with an ALB.

D.DNS validation failed during renewal.

AnswerB

After ACM renewal, the listener must be updated to use the new certificate.

Why this answer

Option A is correct because ACM automatically renews certificates but the ALB may not use the new certificate until it is redeployed or the listener is updated. Option B is wrong because the certificate is public and can be used with an ALB. Option C is wrong because ACM uses DNS validation with Route 53 automatically.

Option D is wrong because ACM does not need to import the certificate; it issues it.

Full explanation →

1116

MCQmedium

A company needs to connect its on-premises data center to AWS using AWS Direct Connect. The company has two redundant connections and wants to use BGP as the routing protocol. Which BGP attribute should be manipulated to influence outbound traffic from AWS to the on-premises network?

A.Set the Local Preference attribute on routes received from AWS.

B.Prepend AS_PATH on routes advertised to AWS.

C.Set the MED attribute on routes advertised to AWS.

D.Apply a BGP community tag to routes received from AWS.

AnswerB

AS_PATH prepend makes a path less preferred for outbound traffic from AWS.

Why this answer

Option C is correct because the AS_PATH prepend attribute can be used to influence outbound traffic from AWS by making one path less preferred. Option A is wrong because MED influences inbound traffic. Option B is wrong because Local Preference is used within an AS to influence outbound traffic, but it is not sent to peers.

Option D is wrong because the community attribute can be used for various routing policies but not directly for outbound traffic influence in this context.

Full explanation →

1117

MCQmedium

A company has a VPC with a CIDR block of 10.0.0.0/16 and needs to connect to a partner's VPC with CIDR 10.0.0.0/16. The VPCs are in the same Region. What is the best solution?

A.Use an AWS Site-to-Site VPN connection

B.Establish VPC peering between the two VPCs

C.Use an AWS Transit Gateway with a transit gateway attachment and configure NAT on the transit gateway to translate IPs

D.Use an AWS Direct Connect private virtual interface

AnswerC

Transit Gateway can perform NAT to resolve overlapping CIDRs.

Why this answer

Since the CIDRs overlap, VPC peering cannot be used because overlapping CIDRs are not allowed for peering. The best solution is to use a transit gateway with network address translation (NAT) to handle the overlapping IPs. Option C is correct.

Option A (VPC peering) is not possible. Option B (VPN) would also have overlapping issues. Option D (Direct Connect) does not solve overlapping.

Full explanation →

1118

MCQmedium

A company is using AWS Client VPN to allow remote employees to access resources in a VPC. The security team wants to enforce multi-factor authentication (MFA) for all VPN connections. Which configuration should be used?

A.Attach a security group to the Client VPN endpoint that only allows MFA-authenticated traffic

B.Use AWS Managed Microsoft AD for authentication

C.Use mutual authentication with client certificates

D.Use SAML-based federation with an identity provider that requires MFA

AnswerD

SAML federation allows integration with an IdP that can enforce MFA.

Why this answer

AWS Client VPN supports mutual authentication and can use SAML-based identity federation with an IdP that requires MFA. Option A is wrong because client certificates alone do not enforce MFA. Option B is wrong because Active Directory alone does not enforce MFA.

Option D is wrong because security groups do not enforce authentication.

Full explanation →

1119

MCQhard

Refer to the exhibit. A company has attached this bucket policy to an S3 bucket. An EC2 instance in VPC vpc-12345 is trying to access the bucket but is getting access denied. The EC2 instance has a public IP of 198.51.100.10. What is the MOST likely reason?

A.The policy does not have an explicit allow for the instance's IP

B.The EC2 instance's source IP is not in the allowed IP range

C.Both conditions must be met for access

D.The EC2 instance does not have the s3:GetObject permission

AnswerB

The instance has a different public IP; the IP condition is not met, and the VPC condition only applies if accessed via VPC endpoint.

Why this answer

Option B is correct. The policy has two allow statements: one for source IP range and one for source VPC. The EC2 instance's source IP (198.51.100.10) is not in the allowed IP range (203.0.113.0/24).

The second statement allows requests from the VPC, but the condition aws:SourceVpc is only present when the request comes through a VPC endpoint (Gateway or Interface endpoint). If the EC2 instance accesses S3 via the internet (public IP), the aws:SourceVpc condition is not satisfied, so the second statement does not apply. The first statement does not allow the IP, resulting in implicit deny.

Option A is wrong because the policy allows GetObject. Option C is wrong because the policy does not require both conditions. Option D is wrong because there is no explicit deny.

Full explanation →

1120

MCQeasy

A network engineer created the CloudFormation stack shown. After creation, an EC2 instance launched in PublicSubnet does not have a public IP address. What is the most likely reason?

A.The VPC does not have an Internet Gateway attached

B.The subnet does not have an Internet Gateway attached

C.The subnet's route table does not have a route to a NAT Gateway

D.The instance type does not support public IP addresses

AnswerA

Without an Internet Gateway, instances cannot be assigned public IPs or reach the internet.

Why this answer

The subnet property 'MapPublicIpOnLaunch' is set to true, but the VPC does not have an Internet Gateway attached, and the subnet's route table does not have a route to an Internet Gateway. Without an Internet Gateway, public IP assignment might not work as expected, or the instance cannot reach the internet.

Full explanation →

1121

MCQhard

A company is deploying a global application with users in North America and Europe. The application runs on EC2 instances in us-east-1 and eu-west-1. To reduce latency, the company wants to route users to the nearest region and provide automatic failover. Which combination of AWS services should be used?

A.Amazon CloudFront with origins in each region.

B.AWS Global Accelerator with endpoint groups in each region.

C.Amazon Route 53 with geolocation routing and health checks.

D.Amazon Route 53 with latency-based routing and health checks.

AnswerD

Latency routing directs users to the lowest-latency region, health checks provide failover.

Why this answer

Option D is correct because Amazon Route 53 latency-based routing directs users to the region with the lowest latency, automatically routing traffic to the nearest region. Combined with health checks, if an endpoint fails, Route 53 automatically fails over to the next lowest-latency healthy endpoint, meeting both the latency reduction and automatic failover requirements.

Exam trap

AWS often tests the distinction between geolocation routing (which uses static geographic mapping) and latency-based routing (which uses dynamic network performance data), and candidates mistakenly choose geolocation routing because they think 'nearest region' means geographic proximity rather than network latency.

How to eliminate wrong answers

Option A is wrong because Amazon CloudFront is a content delivery network (CDN) that caches content at edge locations; it does not provide active-active routing or automatic failover between regional origins based on user proximity for dynamic application traffic—it primarily accelerates static and dynamic content delivery via edge caching, not regional routing with health-check-based failover. Option B is wrong because AWS Global Accelerator uses endpoint groups to route traffic to the nearest region via Anycast IPs, but it does not natively support automatic failover between endpoint groups based on health checks—failover requires manual intervention or additional automation, and Global Accelerator is designed for TCP/UDP traffic optimization, not DNS-level routing with health-check-driven failover. Option C is wrong because Amazon Route 53 geolocation routing routes traffic based on the user's geographic location, not latency; it does not automatically fail over to the next nearest region if the primary region is unhealthy—geolocation routing requires explicit failover rules (e.g., failover routing) and does not dynamically adjust to latency changes.

Full explanation →

1122

MCQeasy

A company wants to ensure that traffic between Amazon EC2 instances in the same VPC but different subnets is inspected by a network security appliance. The appliance is deployed in a separate security VPC. Which AWS service should be used to route traffic through the security VPC?

A.AWS Transit Gateway

B.VPC Peering

C.VPC Endpoint

D.Network Load Balancer

AnswerA

Transit Gateway can route traffic between VPCs with route tables enabling inspection.

Why this answer

Option B is correct because Transit Gateway with route tables allows inter-VPC traffic to be forwarded to the security VPC. Option A is wrong because VPC Peering does not support transitive routing. Option C is wrong because an NLB is a load balancer, not a routing device.

Option D is wrong because VPC endpoints are for accessing AWS services.

Full explanation →

1123

MCQmedium

A security engineer needs to audit all API calls made in an AWS account for compliance. The engineer wants to capture the source IP address and the user agent for each call. Which AWS service should be used?

A.AWS Config

B.AWS CloudTrail

C.Amazon CloudWatch Logs

D.VPC Flow Logs

AnswerB

CloudTrail logs API calls with source IP and user agent.

Why this answer

AWS CloudTrail records API calls and includes source IP and user agent. Option B is wrong because VPC Flow Logs capture network traffic, not API calls. Option C is wrong because CloudWatch Logs stores logs but does not capture API calls directly.

Option D is wrong because AWS Config records resource changes, not API calls.

Full explanation →

1124

MCQhard

A global e-commerce company uses AWS CloudFront to distribute content. They have an origin behind an Application Load Balancer (ALB) in a VPC. The ALB is internet-facing and has a security group that allows inbound HTTPS traffic from CloudFront's IP ranges. Users in some regions report slow loading times. The company wants to reduce latency and improve performance. They are considering using Lambda@Edge and origin failover. However, they also notice that the ALB is receiving traffic directly from some IPs that are not CloudFront IPs, causing unnecessary load. What should a network engineer do to restrict access to the ALB to only CloudFront?

A.Update the ALB security group to allow inbound HTTPS only from the CloudFront managed prefix list

B.Use AWS WAF to block requests that do not come from CloudFront IPs

C.Configure the ALB to require a custom header (e.g., X-Origin-Verify) and validate it in the origin

D.Set up a VPC endpoint for CloudFront to route traffic privately

AnswerA

This restricts access to CloudFront IPs only.

Why this answer

The best practice is to restrict ALB security group to CloudFront managed prefix list (com.amazonaws.global.cloudfront.origin-facing). This dynamically allows CloudFront IPs. Option A (custom header) is good but not sufficient alone because attackers can mimic headers.

Option B (AWS WAF) can help but is not the primary method. Option D (restrict to specific regions) is not precise.

Full explanation →

1125

MCQhard

A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network team notices that traffic to a particular EC2 instance is taking a suboptimal path that goes through the internet instead of Direct Connect. The EC2 instance has both a private IP and a public IP. The on-premises router is advertising the VPC's CIDR block over BGP. What is the most likely cause?

A.The private VIF is not configured to route the VPC CIDR.

B.The security group on the EC2 instance is blocking traffic from the on-premises IP range.

C.The on-premises router is not advertising the VPC CIDR to the Direct Connect router.

D.The on-premises DNS is resolving the EC2 instance's public IP address instead of its private IP address.

AnswerD

When using Direct Connect, you should use private IP addresses to ensure traffic stays on the private network.

Why this answer

If the on-premises router uses the public IP to reach the instance, traffic will go over the internet, not Direct Connect. The issue is that the on-premises DNS or routing is resolving the public IP instead of the private IP for the instance. Option B is correct.

Option A is incorrect because the private VIF is designed for private IP traffic. Option C is incorrect because security groups do not affect routing paths. Option D is incorrect because the BGP advertisement of the VPC CIDR is correct.

Full explanation →

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