Network Implementation questions on this certification test your ability to deploy and manage network implementation concepts in scenario-based situations.
Start practicing
Network Implementation — choose a session length
Free · No account required
Domain overview
Use this page to practise Network Implementation questions for this certification. Focus on how the exam tests network implementation in scenario format — understanding the why behind each answer builds more durable knowledge than memorising options.
Exam objectives
Core Network Implementation concepts and how they apply in real-world cloud scenarios.
How to deploy network implementation correctly and verify the outcome.
Troubleshooting network implementation issues by interpreting error output and system state.
Cloud best practices and Network Implementation design trade-offs tested by this certification.
Selecting the most expensive service when a simpler managed option meets the requirement.
Forgetting that cloud resources must be explicitly secured — defaults are rarely secure.
Choosing a global service fix when the issue is region-specific.
Overlooking cost implications of cross-region data transfer in architecture questions.
Click any question to see the full explanation and answer options, or start a focused practice session above.
A company is deploying a multi-tier web application across two AWS Regions. The application uses an Application Load Balancer (ALB) in each region, and traffic must be distributed to the closest healthy ALB using Route 53 latency-based routing. The application requires that clients maintain the same source IP address when the request is forwarded from the ALB to the backend targets. The backend targets are EC2 instances in private subnets. The company also needs to ensure that traffic between the ALB and targets stays within AWS. What should the company implement to meet these requirements?
2A company has a Direct Connect connection with a private VIF connected to a VPC. The company wants to add a second Direct Connect connection for redundancy. They plan to use BGP AS_PATH prepending to influence traffic steering so that the primary connection is preferred for inbound traffic. The on-premises router advertises the same prefix over both connections. The company configures BGP on the primary VIF with AS_PATH prepending (prepend two AS numbers). However, after configuration, inbound traffic still uses both paths equally. What is the most likely cause?
3A networking engineer is troubleshooting connectivity issues between two VPCs that are peered using a VPC peering connection. The VPCs are in different AWS accounts. The engineer has verified that the route tables are correct and the security groups allow traffic. However, ICMP ping fails from an instance in VPC A to an instance in VPC B. What is a likely cause?
4A company has a centralized inspection VPC architecture where all traffic from spoke VPCs is routed through a Transit Gateway to a centralized VPC that hosts firewall appliances (NGFW). The company needs to inspect traffic between two instances in the same spoke VPC. What is the simplest way to achieve this?
5A company is implementing a hybrid network with AWS Direct Connect and a VPN connection as backup. They have a Direct Connect gateway (DXGW) attached to a private VIF and a virtual private gateway (VGW) attached to a VPN connection. The VPC is attached to the VGW. They want to use the Direct Connect connection for all traffic when available. The on-premises router advertises the same prefix over both connections. However, traffic from on-premises to the VPC is using the VPN connection. BGP is configured correctly on both connections. What should the company do to prefer the Direct Connect path?
6A company is designing a network for a three-tier web application on AWS. The web tier must be accessible from the internet, and the application and database tiers must be in private subnets. The company wants to use a single AWS Region and ensure high availability. Which TWO configurations should be implemented? (Choose two.)
7A company is migrating a legacy application to AWS. The application requires multicast communication between EC2 instances in the same VPC. Which THREE options can support this requirement? (Choose three.)
8A company is deploying a VPC with public and private subnets in two Availability Zones. They need to ensure that instances in private subnets can access the internet for software updates while remaining unreachable from the internet. Which solution meets these requirements?
9A company has deployed a web application across multiple AWS Regions using Application Load Balancers (ALBs) and EC2 instances. They want to use AWS Global Accelerator to improve performance and provide a fixed entry point. The Global Accelerator is configured with endpoints pointing to the ALBs. However, users are experiencing intermittent failures. What is the most likely cause?
10A network engineer is troubleshooting connectivity between two VPCs (VPC-A and VPC-B) connected via a VPC peering connection. Both VPCs have CIDR blocks: VPC-A = 10.0.0.0/16, VPC-B = 10.1.0.0/16. An EC2 instance in VPC-A (10.0.1.10) cannot ping an EC2 instance in VPC-B (10.1.1.10). Security groups and NACLs allow all traffic. The route tables are configured as follows: In VPC-A, a route to 10.1.0.0/16 via the peering connection. In VPC-B, a route to 10.0.0.0/16 via the peering connection. What is the most likely cause?
11A company is setting up a Direct Connect connection to connect its on-premises data center to AWS. The connection is established, and a private virtual interface (VIF) is configured. The on-premises router can ping the VIF's Amazon side IP address, but cannot ping an EC2 instance in the VPC. The VPC has a virtual private gateway attached, and the route tables are correctly configured. What should the company check next?
12A company has a VPC with a CIDR of 10.0.0.0/16 and has enabled VPC Flow Logs to capture all traffic. The logs show that an EC2 instance (10.0.1.10) is sending outbound traffic to an external IP (203.0.113.50) on port 443, but the traffic is being rejected. The instance's security group allows outbound HTTPS to 0.0.0.0/0, and the subnet's NACL allows outbound traffic on port 443. The VPC has an internet gateway attached, and the route table directs 0.0.0.0/0 to the internet gateway. What is the most likely cause of the rejection?
13A network engineer is designing a hybrid network architecture that connects an on-premises data center to AWS using AWS Direct Connect and a VPN connection as a backup. The on-premises network uses BGP to advertise routes to AWS. Which of the following are best practices for this setup? (Choose TWO.)
14A company has a VPC with multiple subnets spanning three Availability Zones. They have deployed an Application Load Balancer (ALB) in the VPC and need to ensure high availability and scalability for a web application. Which of the following are design considerations for implementing the ALB in this environment? (Choose THREE.)
15A network engineer is analyzing VPC Flow Logs for a VPC with CIDR 10.0.0.0/16. The exhibit shows a sample log entry. The engineer notices that traffic from 10.0.1.10 to 10.0.2.10 on port 443 is being accepted. However, the application team reports that the connection is failing. What is the most likely reason for the disconnect?
16A company has set up a transit gateway with attachments to VPC-A and VPC-B. The transit gateway route table shows routes to both VPCs and a blackhole for 0.0.0.0/0. VPC-A's public subnet route table sends 10.1.0.0/16 traffic to the transit gateway. However, an EC2 instance in VPC-A's public subnet cannot reach an instance in VPC-B. What is the most likely cause?
17A company is deploying a new VPC with both public and private subnets. The public subnet hosts an internet-facing Application Load Balancer (ALB), and the private subnet hosts EC2 instances running a web application. The EC2 instances need to download updates from the internet, but they must not be directly accessible from the internet. Which combination of steps should a network engineer implement to meet these requirements?
18A company has a Direct Connect connection with a private VIF connected to a VPC. The network engineer notices that traffic from on-premises to the VPC is being dropped intermittently. The on-premises router shows BGP session is up, but the VPC route table does not have the on-premises prefix. What is the most likely cause?
19A company wants to ensure that traffic between two VPCs in the same region is encrypted in transit. The VPCs are connected via a VPC peering connection. What should the network engineer do to meet this requirement?
20A network engineer is troubleshooting connectivity issues from an on-premises network to an AWS VPC over a Direct Connect private VIF. The VPC has a virtual private gateway attached. The on-premises router can ping the private IP of an EC2 instance in the VPC, but application traffic (TCP port 443) fails. What is the most likely cause?
21A company is using AWS Transit Gateway to interconnect multiple VPCs and on-premises networks. The network engineer needs to ensure that traffic between VPC A and VPC B follows a specific path through a Network Virtual Appliance (NVA) in VPC C. Which TWO actions should the engineer take?
22A company has a VPC with public and private subnets. The public subnet has a NAT Gateway. The private subnet instances need to access an S3 bucket in the same region. Which THREE steps should the network engineer take to ensure the most cost-effective and secure access without traversing the internet?
23A company has a large AWS environment with hundreds of VPCs connected via a Transit Gateway. The network team is implementing a new hub-and-spoke architecture where all traffic between VPCs must be inspected by a centralized firewall appliance in a shared services VPC. The firewall appliance is a third-party virtual appliance that supports VRF-like segmentation. The network engineer has configured the Transit Gateway with separate route tables for each VPC, and the shared services VPC is associated with all route tables. The firewall appliance is deployed in the shared services VPC with two ENIs: one in a 'trust' subnet and one in an 'untrust' subnet. The trust subnet is used for traffic coming from spoke VPCs, and the untrust subnet is used for traffic going to other spoke VPCs. The firewall appliance performs stateful inspection and returns traffic to the Transit Gateway via the correct ENI. However, after implementation, traffic between two spoke VPCs (VPC A and VPC B) is being dropped. The engineer verifies that the Transit Gateway route tables have static routes for each spoke VPC CIDR pointing to the shared services VPC attachment. The spoke VPCs have routes to each other's CIDR via the Transit Gateway. The firewall logs show that traffic from VPC A reaches the trust ENI, but the firewall is unable to send traffic to VPC B because it does not have a route to VPC B's CIDR. What is the most likely cause?
24A company is deploying a hybrid network architecture with an AWS Site-to-Site VPN connection between its on-premises network and a VPC. The on-premises network uses BGP to advertise routes to the VPN connection. After the VPN is established, the on-premises network cannot reach EC2 instances in the VPC. The VPC route table has a route for the on-premises CIDR block pointing to the VPN gateway. What is the most likely cause of this issue?
25A 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.)
26Order the steps to set up a Network Load Balancer with a TCP listener in front of an Auto Scaling group:
27Order the steps to set up a redundant Direct Connect connection with two virtual interfaces in different AWS regions:
28Match each AWS security feature to its description.
29Match each AWS networking monitoring or troubleshooting tool to its primary purpose.
30A company is deploying a new web application on AWS. They need to distribute incoming HTTPS traffic across multiple EC2 instances in different Availability Zones. Which AWS service should they use?
31A company has set up a site-to-site VPN connection between its on-premises network and AWS. The tunnel status shows 'UP' on both sides, but traffic from on-premises cannot reach EC2 instances in the VPC. What is the most likely cause?
32A company runs a critical application on EC2 instances behind an Application Load Balancer. They need to ensure that if an instance fails health checks, it is automatically terminated and replaced. Which AWS service should they use?
33A company is designing a VPC with public and private subnets. They want EC2 instances in private subnets to be able to access the internet for software updates. Which AWS service should they use?
34A company has multiple VPCs that need to communicate with each other. They want to use a hub-and-spoke model with centralized network management. Which AWS service should they use?
35A company is deploying a latency-sensitive application across multiple AWS Regions. They want to use the AWS global network to route traffic to the nearest edge location for fast content delivery. Which service should they use?
36A company needs to connect its on-premises data center to AWS with a dedicated, private network connection that provides consistent performance. Which AWS service should they use?
37A company has a VPC with multiple subnets. They want to centrally control outbound traffic to the internet and log all traffic. Which AWS service should they use?
38A company is running a two-tier application with a web tier and a database tier. The web tier must be accessible from the internet, but the database tier should only be accessible from the web tier. Which architecture should they use?
39Which TWO of the following are valid options for implementing network segmentation in a VPC?
40Which THREE of the following are valid methods to connect a VPC to an on-premises network?
41Which TWO of the following are characteristics of an AWS Network Load Balancer (NLB)?
42A company is deploying a new application in a VPC with public and private subnets. The application servers in the private subnets need to access the internet to download patches. Which configuration meets this requirement without allowing inbound internet traffic?
43A global company wants to connect multiple VPCs across different AWS Regions using a hub-and-spoke model. The hub VPC contains shared services such as Active Directory and DNS. Which AWS service provides the most scalable and maintainable solution for this architecture?
44A company has a Direct Connect connection with a private virtual interface (VIF) to a VPC. The on-premises network uses BGP to advertise a route for 10.0.0.0/8. The VPC CIDR is 10.1.0.0/16. The company wants to ensure that all traffic from the VPC to on-premises uses the Direct Connect connection, but if the Direct Connect fails, traffic should fail over to a VPN connection. Which configuration achieves this?
45A company wants to enable DNS resolution for hybrid network using Route 53 Resolver. The on-premises DNS servers are reachable via Direct Connect. The company wants to forward queries for a custom domain (example.corp) from VPC to on-premises. Which resource should be created in the VPC?
46A company has a VPC with public and private subnets. An EC2 instance in a private subnet needs to access an S3 bucket in the same Region. Which solution provides the most secure and cost-effective connectivity?
47A company has multiple AWS accounts and wants to centrally manage network security using AWS Network Firewall. The firewall must inspect traffic between VPCs in the same Region. Which deployment model achieves this with minimal latency?
48A company has a VPC with an application load balancer (ALB) in public subnets and EC2 instances in private subnets. The EC2 instances must only accept traffic from the ALB. Which security group configuration achieves this?
49A company has a Direct Connect connection with a public virtual interface (VIF) to access AWS public services. They want to ensure that all traffic to Amazon S3 from on-premises uses the Direct Connect connection instead of the internet. Which configuration is required?
50A company has a VPC with a CIDR of 10.0.0.0/16 and needs to connect to an on-premises network using AWS Site-to-Site VPN. The on-premises network uses 10.0.0.0/8. The company wants to ensure that traffic to on-premises from VPC does not overlap with VPC's own CIDR. Which action should be taken?
51Which TWO of the following are valid methods to connect a VPC to an on-premises network? (Choose TWO.)
52Which THREE of the following are considerations when designing a VPC with multiple Availability Zones for high availability? (Choose THREE.)
53Which TWO of the following are required to establish a BGP session over a Direct Connect private virtual interface? (Choose TWO.)
54A company is deploying an application across multiple Availability Zones in a single AWS Region. The application requires that all traffic between EC2 instances in the same subnet be inspected by a network appliance. Which configuration should be used to meet this requirement?
55A company has multiple VPCs connected via a Transit Gateway. The security team wants to centrally inspect all traffic between VPCs using a third-party firewall appliance. The appliance must be deployed in a single VPC and all inter-VPC traffic must be routed through it. Which architecture should be used?
56A company has a Direct Connect connection with multiple Virtual Interfaces (VIFs) to an on-premises network. The VIFs are associated with a Direct Connect Gateway that is attached to multiple VPCs. The company is experiencing asymmetric routing and wants to ensure that traffic from on-premises to the VPCs always uses the same VIF. Which configuration should be implemented?
57A company uses AWS Site-to-Site VPN to connect its on-premises network to a VPC. The VPN connection uses static routes. Recently, the on-premises network administrator added a new subnet (10.0.3.0/24) and needs to ensure that traffic to this subnet is routed through the VPN tunnel. What must be done in the AWS VPC to enable this connectivity?
58A company has a VPC with public and private subnets. The private subnets need to access the internet for software updates. The company wants to ensure that traffic can only go out to the internet and not be initiated from the internet. Which configuration should be used?
59A company is migrating a legacy application to AWS. The application requires multicast communication between instances. The company needs to implement a multicast solution within a VPC. Which AWS service or feature should be used to support multicast?
60A company needs to connect its on-premises network to a VPC using AWS Direct Connect. The company wants to use a single Direct Connect connection to connect to multiple VPCs in the same region. Which configuration should be used?
61A company has a VPC with an Application Load Balancer (ALB) that distributes traffic to EC2 instances in private subnets. The ALB needs to be accessible from the internet. The security team requires that all traffic to the ALB be inspected by AWS WAF. Which configuration meets these requirements?
62A company has a Direct Connect connection with a private VIF to a VPC. The VPC has a subnet that hosts an EC2 instance with a sensitive database. The company wants to add an extra layer of encryption for traffic between the on-premises network and the EC2 instance. Which solution should be used?
63Which TWO of the following are valid methods to connect an on-premises network to an Amazon VPC? (Select TWO.)
64Which THREE of the following are features of AWS Transit Gateway? (Select THREE.)
65A company is designing a multi-region architecture using AWS Direct Connect. Which TWO of the following are valid configurations for connecting to multiple regions? (Select TWO.)
66A company is deploying a multi-tier web application in a VPC with public and private subnets. The web servers in the public subnets must be able to initiate outbound connections to the internet for software updates, but must not be directly accessible from the internet. Which configuration meets these requirements?
67A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network uses BGP to advertise a specific prefix (10.0.0.0/16) to the VPC. Recently, the company deployed a new VPC with CIDR 10.0.0.0/16 in a different region and established a VPC peering connection between the two VPCs. Now, traffic from on-premises to the new VPC is being routed to the old VPC instead. How should the company resolve this issue?
68A company wants to provide internet access to instances in a private subnet while ensuring that traffic is logged and inspected. The solution must be highly available within a single AWS Region. Which approach should the company use?
69A company has deployed an application across multiple AWS Regions using Application Load Balancers (ALBs). The company wants to route traffic to the nearest healthy endpoint using latency-based routing. Which AWS service should be used to distribute traffic across the ALBs?
70A company has a Direct Connect connection with a private VIF to a VPC. The company also has a Site-to-Site VPN connection to the same VPC as a backup. During a failover test, traffic from on-premises to the VPC continues to use the Direct Connect even after it is intentionally failed. The BGP timers are set to default values. What is the most likely cause?
71A company needs to securely connect multiple VPCs across different AWS Regions using AWS backbone network infrastructure without traversing the public internet. The solution must be managed centrally and support transitive routing between VPCs. Which service should the company use?
72A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to download patches from an S3 bucket in the same region. The company wants to minimize data transfer costs and avoid traversing the internet. Which solution should the company implement?
73A network engineer is troubleshooting high latency on a Direct Connect connection. The engineer notices that the BGP session is flapping intermittently. The connection is a 1 Gbps dedicated connection with a single private VIF. The router configuration uses default BGP timers. What is the most likely cause of the flapping?
74A company has a VPC with multiple subnets across three Availability Zones. The company wants to deploy a Network Load Balancer (NLB) to distribute TCP traffic to a fleet of EC2 instances. The NLB must preserve the source IP address of the client. Which configuration is required?
75A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network advertises the prefix 10.0.0.0/8 to AWS. The VPC has a CIDR of 10.0.0.0/16. A network engineer wants to ensure that traffic from on-premises to a specific subnet 10.0.1.0/24 in the VPC is routed via a dedicated VPN connection instead of Direct Connect for testing purposes. Which TWO actions should the engineer take?
76A company is designing a hybrid network using AWS Direct Connect and a Site-to-Site VPN as a backup. The company has two Direct Connect connections from different providers for redundancy. The company wants to use BGP to automatically fail over to the VPN if both Direct Connect connections fail. Which TWO configurations are required to achieve this?
77A company has a VPC with a CIDR of 10.0.0.0/16 and needs to connect to an on-premises network using AWS Direct Connect and a Site-to-Site VPN. The on-premises network advertises 10.0.0.0/8 over BGP. The company wants to ensure that traffic to the VPC's specific subnet 10.0.1.0/24 is routed via the VPN, while all other traffic to 10.0.0.0/8 uses Direct Connect. Which THREE actions should the network engineer take?
78A company is deploying a VPC with public and private subnets in two Availability Zones. The public subnets contain NAT gateways for outbound internet access from the private subnets. The private subnets host web servers that need to make API calls to an external service over the internet. After implementation, the web servers cannot reach the internet. Which configuration is the most likely cause?
79A network engineer is setting up a Direct Connect connection from an on-premises data center to AWS. The connection uses a private VIF to connect to a VPC via a Direct Connect gateway. The on-premises network is advertising a BGP prefix 10.0.0.0/16, which overlaps with the VPC CIDR 10.0.0.0/16. What is the expected behavior?
80An organization uses AWS Transit Gateway to connect multiple VPCs and on-premises networks via VPN. They want to implement traffic inspection between VPCs using a third-party firewall appliance in a central VPC. The firewall must inspect traffic for all inter-VPC flows. Which architecture meets this requirement?
81A company has a VPC with an IPv6 CIDR block and wants to provide internet access to instances in a private subnet using an egress-only internet gateway. Which of the following must be configured correctly?
82A company is implementing a multi-region architecture with VPCs in us-east-1 and eu-west-1. They want to connect these VPCs using a Transit Gateway and ensure that traffic between regions can be inspected by a firewall in us-east-1. Which configuration is required?
83A developer wants to allow an EC2 instance in a VPC to access an Amazon S3 bucket without traversing the public internet. Which AWS service should be used?
84A company has a VPN connection between an on-premises network and AWS using two tunnels for redundancy. The BGP sessions are established, but traffic is only flowing through one tunnel. The engineer wants to ensure both tunnels are actively used. What should be configured?
85An organization is using AWS Direct Connect with a private VIF to connect to a VPC. They want to extend connectivity to multiple VPCs in the same region without creating multiple private VIFs. Which solution should they implement?
86A company has a VPC with a public subnet and a private subnet. They launch an EC2 instance in the private subnet with a private IP only. The instance needs to download patches from the internet. Which configuration is required?
87A network engineer is troubleshooting connectivity issues between two VPCs connected via a Transit Gateway. The VPCs are in the same region and have proper route tables. Which TWO actions should the engineer perform to diagnose the problem?
88An organization is designing a hybrid network using AWS Direct Connect with a private VIF. They want to ensure high availability and failover. Which THREE components should be part of the design?
89A company is deploying an application across multiple VPCs using AWS Transit Gateway. They need to ensure that only specific VPCs can communicate with each other. Which TWO methods can be used to isolate traffic?
90A company is using AWS Client VPN to provide remote access to their VPC. Users report that they can connect to the VPN but cannot reach resources in the VPC. Which THREE configuration items should the engineer verify?
91An engineer is reviewing VPC Flow Logs for connectivity issues between two EC2 instances (10.0.1.5 and 10.0.2.10) on TCP port 443. The first log entry shows ACCEPT, the second shows REJECT. What is the most likely cause of the REJECT?
92An EC2 instance with the attached IAM role is unable to download objects from an S3 bucket. The instance is in a VPC with CIDR 10.0.0.0/16. The S3 bucket policy allows access from the VPC. What is the most likely reason for the failure?
93A company is deploying a hybrid network architecture with an AWS Direct Connect connection. They require high availability with redundant connections to two different AWS Direct Connect locations. Which configuration meets the high availability requirement?
94A company is troubleshooting high latency on an AWS Direct Connect connection. The network team notices that the latency increases during peak hours. The connection uses a single virtual interface (VIF) with a 1 Gbps capacity. What is the MOST likely cause of the latency?
95A company needs to connect multiple VPCs to a common on-premises network through a single AWS Direct Connect connection. Which AWS service should be used to simplify this architecture?
96A company is implementing a multi-region active-active application. They want to route users to the nearest healthy endpoint using DNS. Which AWS service should be used?
97A company has a Direct Connect connection with a private VIF to a VPC. They notice that the BGP session is flapping every few minutes. The network team confirms that the customer router and AWS router are configured correctly. What is the MOST likely cause of the BGP flapping?
98A company is setting up a new VPC with both IPv4 and IPv6 support. They need to ensure that instances in a private subnet can access the Internet for software updates. Which combination of resources is required?
99A company is deploying a web application across multiple Availability Zones in a single region. They want to distribute incoming traffic evenly across all healthy EC2 instances. Which AWS service should be used as the entry point?
100A network engineer is troubleshooting connectivity issues between an on-premises network and a VPC over a Direct Connect private VIF. The on-premises network can reach EC2 instances in the VPC, but cannot reach an RDS database in the same VPC. The VPC has a single subnet. What is the MOST likely cause?
101A company needs to establish a dedicated, private, high-bandwidth connection between its on-premises data center and AWS. Which AWS service should be used?
102A company is designing a highly available network in AWS. They have two Direct Connect connections from different providers to two different AWS Direct Connect locations. They want to use BGP as the routing protocol. Which TWO actions should be taken to ensure high availability?
103A company is deploying a new VPC with public and private subnets. The VPC will host web servers in the public subnet and database servers in the private subnet. The web servers need to access the internet for updates, and the database servers need to receive traffic only from the web servers. Which THREE components are essential for this architecture?
104A company is using AWS Transit Gateway to connect multiple VPCs and an on-premises network via Direct Connect. The network team wants to isolate traffic between VPCs while allowing all VPCs to reach the on-premises network. Which TWO configurations should be implemented?
105A 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?
106A 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?
107A company is implementing a hybrid network using AWS Direct Connect and VPN backup. The company has two Direct Connect connections from different providers and a site-to-site VPN as a backup. The company wants to ensure that traffic is always routed through the Direct Connect connections when they are healthy, and only fails over to the VPN if both Direct Connect connections fail. Which BGP configuration should be used on the customer gateway device (CGW) to achieve this?
108A 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?
109A company is setting up AWS Transit Gateway with multiple VPC attachments and an AWS Direct Connect Gateway. The company wants to control which VPCs can communicate with each other and with the on-premises network. Which TWO actions should the company take to implement this?
110A company is deploying an AWS Client VPN endpoint to provide remote access to its VPC resources. The company wants to allow clients to access resources in multiple subnets within the VPC. Which TWO configurations are necessary?
111A network engineer runs the above command to list VPC endpoints. The engineer notices that the second endpoint (vpce-0b2c3d4e5f6g7h8i9) does not have a policy document displayed. What does this indicate?
112A network engineer runs the above command and sees an ENI (eni-0a1b2c3d4e5f6g7h8) with status 'in-use' but no InstanceId attached. What AWS service is most likely using this ENI?
113A network engineer examines the route table above. The VPC has a CIDR of 10.0.0.0/16. There is a VPC peering connection (pcx-...) to a VPC with CIDR 192.168.0.0/16. However, instances in this route table's subnet cannot communicate with the peered VPC. What is the most likely cause?
114A company is deploying a VPC with public and private subnets in two Availability Zones. The public subnets are used for NAT gateways and an Application Load Balancer (ALB). The private subnets host EC2 instances running a web application. What is the most cost-effective and highly available configuration for internet access from the private instances?
115A company has a Direct Connect connection with a private virtual interface (VIF) to a VPC. The VPC uses a virtual private gateway (VGW). The on-premises network advertises a route to a specific subnet (10.0.0.0/24) via BGP. However, traffic from the VPC to that subnet is failing. What should the network engineer check first?
116A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks via VPN. They want to inspect traffic between VPCs using a centralized network virtual appliance (NVA) in a security VPC. What is the most scalable and highly available design to achieve this?
117A company has a VPC with private subnets that use a NAT gateway for outbound internet access. The NAT gateway is in a public subnet with an Elastic IP. Users report that some applications are failing to connect to external services. Network engineers confirm that the NAT gateway is in the 'available' state and the route tables have a default route (0.0.0.0/0) pointing to the NAT gateway. What is the most likely cause?
118A company is designing a multi-region architecture with two AWS Regions. They need to connect VPCs in each region to an on-premises data center using AWS Direct Connect. They want to minimize latency and use the same BGP ASN on both sides. Which solution meets these requirements?
119A company wants to allow an EC2 instance in a private subnet to download files from an S3 bucket without traversing the internet. Which AWS service should be used?
120A company has a VPC with CIDR 10.0.0.0/16 and needs to connect to another VPC (192.168.0.0/16) using VPC peering. Both VPCs have overlapping CIDRs with some on-premises networks. What must be done to ensure proper routing?
121A company uses AWS Client VPN for remote access. Users report intermittent disconnections. The network engineer notices that the Client VPN endpoint is associated with a single subnet. What change should be made to improve reliability?
122A company has a VPC with both IPv4 and IPv6 CIDRs. They need to allow outbound IPv6 traffic from private subnets to the internet. What should they use?
123Which TWO of the following are requirements for establishing an AWS Direct Connect private virtual interface? (Choose two.)
124Which THREE of the following are valid considerations when designing a multi-VPC architecture using AWS Transit Gateway? (Choose three.)
125Which TWO of the following are true about AWS VPC endpoints? (Choose two.)
126A company is deploying a multi-tier web application on AWS. The web tier runs on EC2 instances behind an Application Load Balancer (ALB), and the application tier runs on EC2 instances that connect to an RDS MySQL Multi-AZ DB instance. The application tier must be isolated from the internet and only accessible from the web tier. Which network implementation meets these requirements with the LEAST administrative overhead?
127A company is implementing a hybrid network architecture with AWS Direct Connect and a VPN backup. The company has two Direct Connect connections from different providers terminating at two AWS Direct Connect locations, each connecting to a separate AWS Transit Gateway in the same region. The VPCs are attached to both transit gateways. The company needs to ensure that traffic from on-premises to VPCs uses the primary Direct Connect connection when available and fails over to the secondary Direct Connect connection, then to the VPN. How should the company configure routing to achieve this?
128A company is setting up AWS Client VPN to allow remote employees to access resources in a VPC. The VPC has a CIDR block of 10.0.0.0/16. The Client VPN endpoint is associated with a subnet 10.0.1.0/24. The company wants to assign client IP addresses from a different CIDR range than the VPC to avoid overlap. Which client CIDR range should the company specify?
129A company is designing a VPC with public and private subnets in two Availability Zones. The private subnets host EC2 instances that need to download patches from the internet. The company wants to minimize costs while ensuring high availability. Which solution meets these requirements?
130A company has an AWS Direct Connect connection with a private VIF to a VPC. The VPC has multiple subnets across two Availability Zones. The company wants to use the Direct Connect connection as the primary path for all traffic from on-premises to the VPC, and use a Site-to-Site VPN as a backup. The on-premises router is configured to advertise a default route via BGP over the Direct Connect, and the VPN also advertises a default route. Which configuration ensures that the Direct Connect path is preferred over the VPN?
131A company is deploying a VPC with IPv6 support. The VPC has a CIDR block of 10.0.0.0/16 and an assigned IPv6 CIDR block of 2600:1f16:xxxx:xxxx::/56. The company wants EC2 instances in a public subnet to be able to communicate with the internet using IPv6. Which configuration is necessary?
132A company is running a stateful firewall appliance in an EC2 instance in a VPC. The appliance inspects traffic between subnets. The company needs to ensure that traffic from the web tier subnet to the application tier subnet passes through the firewall, but the firewall itself must not affect other traffic. Which configuration should the company implement?
133A company has multiple VPCs connected via AWS Transit Gateway. Each VPC has its own route table in the transit gateway. The company wants to restrict traffic between certain VPCs. For example, VPC A should be able to send traffic to VPC B but not to VPC C. VPC B should be able to send traffic to VPC C. Which configuration should the company use?
134A company is setting up a Site-to-Site VPN connection to AWS. The customer gateway device is behind a NAT device that performs address translation. Which tunnel option must be enabled to ensure the VPN tunnel establishes correctly?
135A 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?
136A company is using AWS Direct Connect with a private VIF to connect its on-premises network to a VPC. The VPC has a CIDR 10.0.0.0/16. The on-premises network uses 192.168.0.0/16. The company wants to enable communication between on-premises and the VPC, and also allow the VPC to access the internet via an internet gateway. Which TWO of the following configurations are necessary?
137A company is designing a VPC with multiple subnets. The company wants to use VPC Flow Logs to monitor network traffic. Which TWO of the following are valid destinations for VPC Flow Logs?
138A company is deploying a VPC with public and private subnets. The private subnets need outbound internet access for updates, but must not be directly reachable from the internet. Which AWS service should be used to achieve this?
139A company is designing a multi-region architecture with an Application Load Balancer (ALB) in each region. They want to route users to the nearest healthy ALB using latency-based routing. Which AWS service should be used?
140A network engineer is troubleshooting connectivity issues between two VPCs connected via a VPC peering connection. The VPCs are in different AWS accounts and regions. The engineer can ping the private IP of an instance in the peered VPC from one side, but not from the other. What is the most likely cause?
141A company wants to deploy a web application on EC2 instances behind an Application Load Balancer (ALB). The application must support sticky sessions (session affinity). What configuration is required on the ALB?
142A company is migrating a legacy application that requires static IP addresses for its clients' firewall whitelisting. The application will be hosted on EC2 instances behind a Network Load Balancer (NLB) in a private subnet. Which approach should the company use to provide static IP addresses for outbound traffic?
143A company has a Direct Connect connection with a private VIF to a VPC. They want to extend this connectivity to multiple VPCs in the same region without creating additional VIFs. Which solution should they implement?
144A company wants to restrict outbound traffic from a VPC to only allow HTTPS traffic to a specific list of domains. Which AWS service can be used to achieve this?
145A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to download patches from an S3 bucket. The company wants to minimize data transfer costs and avoid traversing the internet. Which solution should be implemented?
146A company is experiencing intermittent connectivity issues between its on-premises network and AWS via a Direct Connect connection. The link is up, but packet loss is observed. Which test should the network engineer perform first to isolate the issue?
147Which TWO of the following are valid methods to connect an on-premises data center to a VPC in AWS? (Choose 2.)
148Which TWO of the following are true about using a Network Load Balancer (NLB) with AWS PrivateLink? (Choose 2.)
149A company has a VPC with public and private subnets in two Availability Zones. The company hosts a web application on EC2 instances in the private subnets. The application needs to access an S3 bucket. What is the MOST cost-effective and secure way to provide this access?
150Which THREE of the following are considerations when designing a multi-account VPC architecture using AWS Transit Gateway? (Choose 3.)
151A company is setting up a Direct Connect connection to AWS. The on-premises router is configured with a BGP ASN of 65000. The AWS side uses a public ASN of 64512. Which configuration change is required for BGP peering to establish?
152A company is migrating on-premises workloads to AWS using AWS Direct Connect. The company has two Direct Connect connections from different providers for redundancy. Which configuration ensures seamless failover with automatic traffic rerouting?
153A network engineer is designing a VPC with public and private subnets. The private subnets must have outbound internet access but not be directly reachable from the internet. Which AWS service should be used?
154A company has a multi-account AWS Organizations setup with hundreds of VPCs across multiple regions. The network team needs to centralize outbound internet traffic through a set of inspection VPCs for security monitoring. Which solution is MOST scalable and cost-effective?
155A company has a VPC with a transit gateway (TGW) connected to multiple VPCs and an on-premises network via AWS Direct Connect. The on-premises network advertises a specific prefix 10.0.0.0/16. A VPC attachment in the same region also advertises the same prefix. The TGW route table has the on-premises route as static and the VPC route as propagated. Which route will be used for traffic destined to 10.0.0.5?
156An application running on EC2 instances in a private subnet needs to send logs to Amazon CloudWatch Logs. Which step is essential to allow this communication without traversing the internet?
157A company has a VPC with a CIDR block of 10.0.0.0/16 and needs to establish connectivity to an on-premises network via AWS Site-to-Site VPN. The on-premises network uses a CIDR block of 192.168.0.0/16. The VPN connection will be redundant using two tunnels. Which TWO actions are required to enable this connectivity?
158A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network uses BGP to advertise its prefixes. Recently, the on-premises router started advertising a more specific route (10.0.0.0/24) that overlaps with the VPC's CIDR (10.0.0.0/16). What is the impact on traffic destined to 10.0.0.5?
159A company is deploying a global application and wants to use AWS Global Accelerator to improve performance. The application runs behind an Application Load Balancer (ALB) in us-east-1. Which THREE components are part of a Global Accelerator deployment?
160A company is deploying a multi-tier application across multiple VPCs connected via AWS Transit Gateway. The web tier must be able to initiate connections to the app tier, but the app tier must not be able to initiate connections to the web tier. How can this be achieved?
161A network engineer needs to monitor network traffic in a VPC. Which TWO AWS services can capture and analyze VPC flow logs?
162A company needs to connect its on-premises data center to AWS using a site-to-site VPN. The on-premises firewall does not support IPsec. What alternative solution can the company use?
163Refer to the exhibit. A subnet is created in VPC vpc-abcde but no explicit route table association is set. What is the default route for internet-bound traffic from this subnet?
164A company uses AWS Transit Gateway to connect multiple VPCs. The network team notices that traffic between two VPCs is taking a suboptimal path through a third VPC. What is the most likely cause?
165Refer to the exhibit. After deploying this CloudFormation stack, the VPC is attached to the transit gateway. However, routes are not being propagated to the transit gateway route table. What is the most likely cause?
166A company has a VPC with an IPv4 CIDR of 10.0.0.0/16 and needs to add IPv6 support for its public-facing web application. The application must be accessible via both IPv4 and IPv6. The VPC already has an Internet Gateway attached. What is the correct set of steps to enable IPv6?
167Refer to the exhibit. A flow log record shows ACCEPT for traffic from 10.0.1.5 to 10.0.2.10 on port 443. Which AWS service is most likely the destination?
168Which TWO of the following are valid methods to connect multiple VPCs together in a hub-and-spoke topology while maintaining centralized control? (Choose two.)
169A 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?
170Which TWO of the following are best practices for securing a VPC with AWS Network Firewall? (Choose two.)
171A company has multiple VPCs connected via a transit gateway. Each VPC has a security group that allows traffic from the other VPCs' CIDR blocks. The security group rules are getting complex. How can the company simplify security group management while maintaining the same level of security?
172Which THREE of the following are considerations when designing a Direct Connect implementation for high availability? (Choose three.)
173A company is deploying a public-facing web application on EC2 instances behind an Application Load Balancer. The ALB is configured to terminate HTTPS using a certificate from AWS Certificate Manager. What additional step is required to ensure the ALB can validate the certificate?
174A 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?
175A network engineer is troubleshooting high latency between two EC2 instances in the same VPC but in different Availability Zones. The instances are in the same security group and have proper rules. Which configuration is most likely causing the latency?
176A company has deployed a web application behind an Application Load Balancer (ALB) in a VPC with public and private subnets. The ALB is in public subnets, and the web servers are in private subnets. Clients report intermittent connection errors. Investigation shows that the ALB is marking targets as unhealthy. What is the MOST likely cause?
177A 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?
178A company is migrating a legacy application to AWS. The application requires multicast traffic between EC2 instances. Which AWS service can support multicast within a VPC?
179A financial services company is designing a multi-region architecture for disaster recovery. They have a primary VPC in us-east-1 and a standby VPC in us-west-2. Each VPC has its own CIDR block (10.0.0.0/16 and 10.1.0.0/16). They want to use an inter-region VPC peering connection for replication traffic. Which of the following is a required step to establish this peering connection?
180A company is deploying a web application across multiple Availability Zones in a VPC. The application tier consists of EC2 instances behind an Application Load Balancer (ALB). The security team requires that all traffic between the ALB and the EC2 instances be encrypted. Which solution meets this requirement?
181A company is using AWS Direct Connect to connect its on-premises data center to a VPC. The company wants to use a single Direct Connect connection to connect to multiple VPCs in different AWS accounts. Which AWS service should be used to achieve this?
182A company has a VPC with public and private subnets. An EC2 instance in a private subnet needs to download patches from the internet. The company has a NAT gateway in a public subnet. The EC2 instance can connect to other instances in the VPC but cannot reach the internet. What is the most likely cause?
183A company has a VPC with a public subnet and a private subnet. An EC2 instance in the public subnet is configured as a NAT instance. The company wants to replace the NAT instance with a NAT gateway for better availability and maintenance. After creating a NAT gateway in the public subnet and updating the route table of the private subnet, traffic from the private subnet cannot reach the internet. What is the MOST likely cause?
184A company is designing a hybrid network using AWS Direct Connect. They have two Direct Connect connections from different providers to two different AWS Direct Connect locations. They want to configure a virtual interface (VIF) that provides connectivity to multiple VPCs in the same region. Which type of VIF should they use?
185A company is designing a network architecture for a critical application that requires high availability and low latency. The application will be deployed on EC2 instances in an Auto Scaling group across three Availability Zones in a single region. The instances will communicate with an Amazon RDS database. Which configuration will provide the MOST resilient and performant network connectivity?
186A network engineer is troubleshooting connectivity from an on-premises network to an EC2 instance in a VPC via a Site-to-Site VPN. The VPN tunnel is up, but the engineer cannot ping the EC2 instance's private IP. What should the engineer check first?
187A company has several VPCs in the same AWS account and region. They want to centrally manage and monitor network traffic between these VPCs and also to on-premises networks. Which AWS service should they use?
188A company has a VPC with an IPv4 CIDR block of 10.0.0.0/16. They need to add an IPv6 CIDR block and ensure that traffic from the internet to the IPv6-enabled resources is allowed. Which configuration is required?
189A company is setting up a new VPC with a CIDR block of 10.0.0.0/16. They need to create subnets for different tiers: public (web servers), private (application servers), and database (RDS). They want to maximize the number of available IP addresses while ensuring each subnet has at least 256 IP addresses. Which subnet design meets these requirements?
190A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks. They have a VPC with a CIDR of 10.0.0.0/16 and an on-premises network with CIDR 10.0.0.0/8. The Transit Gateway route table has a static route for 10.0.0.0/8 pointing to the VPN attachment. However, traffic from on-premises to the VPC is not working. What is the most likely cause?
191A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to download patches from the internet. The company has a NAT gateway in the public subnet. The route table for the private subnet has a route 0.0.0.0/0 pointing to the NAT gateway. However, the EC2 instance cannot reach the internet. Which additional configuration is needed?
192A company has a VPC with multiple subnets. An EC2 instance in a private subnet needs to access an S3 bucket. Which AWS service should be used to allow this access without traversing the internet?
193A company is designing a hybrid network using AWS Direct Connect. Which TWO of the following are required to establish a private virtual interface (VIF) to a single VPC?
194A company has a Direct Connect connection with a private virtual interface to a VPC. They want to use the same Direct Connect connection to access another VPC in the same region. Which solution should they implement?
195A company has multiple VPCs that need to communicate with each other and with an on-premises network via AWS Transit Gateway. Which THREE of the following are valid attachment types for a transit gateway?
196A 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?
197A company is troubleshooting connectivity issues between two VPCs that are peered using an inter-region VPC peering connection. The VPCs have the following CIDR blocks: VPC A (10.0.0.0/16) and VPC B (10.1.0.0/16). Which THREE of the following are possible reasons for the connectivity failure?
198A company is designing a highly available architecture for a web application using an Application Load Balancer (ALB) across multiple Availability Zones. Which TWO actions should be taken to ensure high availability?
199A company is deploying a VPC with public and private subnets in two Availability Zones. The public subnets host NAT gateways for outbound internet access from the private subnets. Which configuration ensures that EC2 instances in the private subnets can route traffic to the internet through the NAT gateways?
200A company has a VPC with a CIDR of 10.0.0.0/16. They need to create subnets for a three-tier application. Which THREE subnet CIDR blocks are valid within this VPC?
201A network engineer is troubleshooting connectivity between two EC2 instances in the same VPC but different subnets. The instances can ping each other's private IP addresses, but traffic on TCP port 443 fails. What is the most likely cause?
202A company is setting up 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 configuration items should be checked?
203A company is implementing a hybrid network using AWS Direct Connect and VPN backup. They have multiple VPCs in a single AWS Region. Which design minimizes the number of Direct Connect virtual interfaces while providing connectivity to all VPCs?
204A network engineer is assigned an IAM policy to manage VPC resources. The engineer attempts to create a VPC with CIDR 10.0.0.0/16 and fails. What is the reason?
205An organization needs to securely connect its on-premises data center to multiple VPCs in different AWS Regions. The on-premises network uses BGP. Which AWS service should be used to simplify routing and provide a single point of attachment for the on-premises router?
206A company has a VPC (10.0.0.0/16) with two subnets: public (10.0.1.0/24) and private (10.0.2.0/24). They have an Application Load Balancer (ALB) in the public subnet that distributes traffic to EC2 instances in the private subnet. The ALB is internet-facing and has a security group that allows inbound HTTP/S from 0.0.0.0/0. The EC2 instances have a security group that allows inbound HTTP from the ALB's security group. Users report that they can access the application, but the application is slow and sometimes times out. The network engineer checks CloudWatch metrics and sees that the ALB's target response time is high. The engineer suspects that the EC2 instances are overwhelmed. Which action should the engineer take to improve performance?
207A company is deploying a latency-sensitive application across two AWS Regions using Application Load Balancers (ALBs) and AWS Global Accelerator. The application uses TCP port 8443. Which configuration ensures the lowest possible latency for global users?
208A company has a Direct Connect connection with a private virtual interface (VIF) attached to a Virtual Private Gateway (VGW) that is associated with a single VPC (10.0.0.0/16). The on-premises network uses BGP to exchange routes. The company has recently acquired another company and needs to connect to their VPC (172.16.0.0/16) in the same region. They want to use the existing Direct Connect connection to access both VPCs. The network engineer creates a Transit Gateway, attaches both VPCs, and creates a transit virtual interface (VIF) to the Transit Gateway. The engineer also deletes the private VIF. However, after the change, on-premises users cannot reach either VPC. What should the engineer do to restore connectivity?
209A company is setting up AWS Direct Connect with a 1 Gbps dedicated connection. They want redundant connectivity with automatic failover. What is the most cost-effective way to achieve this?
210A company is deploying a web application across multiple Availability Zones in a VPC. The application needs to be highly available and scale based on traffic. The architecture includes an Application Load Balancer (ALB) in front of EC2 instances in an Auto Scaling group. The company wants to ensure that if an Availability Zone fails, the ALB can still route traffic to healthy instances in other zones. What should the network engineer implement to meet this requirement?
211A company has a VPC with an IPv4 CIDR block of 10.0.0.0/16. They need to add an IPv6 CIDR block to the VPC. Which action should they take?
212A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to access the internet to download software updates. The company has a NAT gateway in the public subnet. The route table for the private subnet has a default route (0.0.0.0/0) pointing to the NAT gateway. However, the EC2 instance cannot access the internet. The network engineer verifies that the NAT gateway has an Elastic IP, the security group for the EC2 instance allows outbound HTTPS traffic, and the network ACL for the private subnet allows inbound and outbound ephemeral ports. What is the most likely cause of the issue?
213A company uses AWS Transit Gateway to connect multiple VPCs and an on-premises network via VPN. The on-premises network advertises a route for 10.0.0.0/8. One VPC has a CIDR of 10.0.1.0/24. How does Transit Gateway handle the overlapping route?
214A company is setting up a Direct Connect connection to AWS. They have a virtual private gateway (VGW) attached to their VPC. They need to establish a single logical connection over the Direct Connect link to access all subnets in the VPC. Which resource should they create on the Direct Connect virtual interface?
215A company is designing a multi-account AWS environment using AWS Organizations. They need to centralize VPC flow logs and network traffic inspection across all accounts. Which architecture meets these requirements with minimal operational overhead?
216A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to access an S3 bucket. The company wants to ensure that traffic to S3 does not traverse the internet. Which solution should a network engineer implement?
217Which TWO of the following are valid methods to connect an on-premises network to an Amazon VPC over a private, dedicated connection? (Select TWO.)
218A company is troubleshooting connectivity between two VPCs (VPC-A and VPC-B) that are peered together. Both VPCs are in the same region. VPC-A has a CIDR of 10.0.0.0/16 and VPC-B has a CIDR of 10.0.0.0/16. The peering connection is established and the route tables are updated. However, EC2 instances in VPC-A cannot ping EC2 instances in VPC-B. What is the most likely cause?
219Which TWO of the following are benefits of using an AWS Transit Gateway over VPC peering for connecting multiple VPCs? (Select TWO.)
220A company has a VPC with multiple subnets. They want to monitor all network traffic entering and leaving the VPC for security analysis. Which AWS service should they use?
221Which THREE of the following are required to configure a site-to-site VPN connection between an on-premises network and an Amazon VPC? (Select THREE.)
222A company is connecting their on-premises data center to AWS using a site-to-site VPN. The customer gateway device has a dynamic routing configuration with BGP. The VPN connection is established, but the VPC route table does not contain the on-premises network routes. What is the most likely cause?
223A company is deploying a VPC with public and private subnets across two Availability Zones. They need to ensure that instances in the private subnets can access the internet for software updates without being directly reachable from the internet. Which AWS service should they use?
224A company has deployed a Network Load Balancer (NLB) in a VPC. The NLB is configured with a target group that points to EC2 instances in the same VPC. The network engineer notices that traffic from clients is not being forwarded to the targets. The NLB's security groups and network ACLs allow all traffic. What is the most likely cause?
225A company has a Direct Connect connection with a private VIF to a VPC. They also have a VPN connection as a backup. They want to ensure that traffic always uses the Direct Connect connection when it is available, and only fails over to the VPN if Direct Connect goes down. How should they configure routing?
226A company wants to securely connect multiple VPCs in the same region to a common on-premises network using a single Direct Connect connection. Which AWS service should they use to simplify the network architecture?
227A company wants to securely connect their on-premises data center to AWS using a site-to-site VPN. They have multiple branch offices that also need to connect to AWS. Which AWS service should they use to simplify the management of multiple VPN connections?
228A company is designing a multi-tier application in a VPC. The web tier must be accessible from the internet, while the application tier must only be accessible from the web tier. The database tier must be isolated from all other tiers except the application tier. Which TWO network architectures meet these requirements? (Choose TWO.)
229A company deployed an Application Load Balancer (ALB) in front of a fleet of EC2 instances. Users report intermittent timeouts. The ALB's target group health checks are failing for some instances. The instances are in private subnets with a single NAT Gateway. What is the most likely cause?
230A company is migrating a legacy application to AWS. The application uses multicast traffic between servers. The company needs to support multicast in the AWS VPC. Which TWO solutions can the network engineer recommend? (Choose TWO.)
231A company has a VPC with a CIDR of 10.0.0.0/16. They create a subnet 10.0.1.0/24 and launch an EC2 instance with a private IP 10.0.1.5. The instance needs to communicate with an on-premises server at 172.16.0.10 over a VPN connection. The VPN connection uses a Virtual Private Gateway. The VPC route table has a route 172.16.0.0/16 pointing to the VPG. The instance cannot reach the on-premises server. What is the most likely cause?
232A company is setting up a site-to-site VPN connection between an on-premises network and AWS. The VPN uses two tunnels for high availability. The network engineer needs to ensure that if one tunnel goes down, traffic automatically fails over to the other tunnel. Which THREE steps should the engineer perform? (Choose THREE.)
233A company wants to use AWS Direct Connect to establish a dedicated network connection from their on-premises data center to AWS. They need to connect to a VPC in the us-east-1 region. Which of the following is a required step in the setup process?
234A company has a VPC with CIDR 10.0.0.0/16. They have two subnets: a public subnet (10.0.1.0/24) and a private subnet (10.0.2.0/24). An Application Load Balancer (ALB) is deployed in the public subnet, and EC2 instances are in the private subnet. The ALB has a target group pointing to the EC2 instances. The security group for the EC2 instances allows traffic from the ALB's security group on port 80. The network ACL for the private subnet allows inbound traffic on port 80 from the public subnet CIDR (10.0.1.0/24) and allows outbound ephemeral ports. However, the ALB health checks are failing with 503 errors. The network engineer checks the ALB logs and sees that TCP connections are established but HTTP requests are timing out. What is the most likely cause?
235A company has a VPC with two subnets: a public subnet with a NAT Gateway and a private subnet. An EC2 instance in the private subnet needs to download patches from the internet. The instance has a security group that allows all outbound traffic. The private subnet's route table has a default route (0.0.0.0/0) pointing to the NAT Gateway. However, the instance cannot reach the internet. What is the most likely issue?
236A company has a VPC with a public subnet and a private subnet. They have a NAT Gateway in the public subnet. They also have an EC2 instance in the private subnet that needs to access the internet. The route table for the private subnet has a default route (0.0.0.0/0) pointing to the NAT Gateway. The security group for the EC2 instance allows outbound HTTPS traffic. The network ACL for the private subnet allows inbound and outbound ephemeral ports. However, the EC2 instance cannot reach the internet. The network engineer checks the NAT Gateway and sees that it has an Elastic IP attached. The engineer also checks the route table for the public subnet and finds no route to the internet. What should the engineer do to fix the issue?
237A company has a VPC with multiple subnets that are peered with another VPC using a VPC Peering connection. They want to ensure that traffic between the two VPCs is encrypted. What should they do?
238A company has a VPC with CIDR 10.0.0.0/16. They have a public subnet (10.0.1.0/24) and a private subnet (10.0.2.0/24). They have a Network Load Balancer (NLB) in the public subnet, and EC2 instances in the private subnet. The NLB has a target group pointing to the EC2 instances. The security group for the EC2 instances allows traffic from the NLB's private IP addresses on port 80. The network ACL for the private subnet allows inbound traffic on port 80 from the public subnet CIDR and outbound ephemeral ports to 0.0.0.0/0. However, clients connecting to the NLB experience intermittent timeouts. The network engineer checks the NLB logs and sees that connections are established but occasionally drop. The engineer also notices that the EC2 instances have a default route to a NAT Gateway in the public subnet. What is the most likely cause of the intermittent timeouts?
239A company needs to provide internet access to a VPC that has both public and private subnets. They have already created an Internet Gateway and attached it to the VPC. What else must be configured for instances in the public subnet to be reachable from the internet?
240A company has deployed a VPC with public and private subnets. The private subnets need outbound internet access for software updates. Which service should be used to provide this access without exposing the instances to inbound traffic?
241A company is designing a highly available network architecture using AWS Direct Connect. They have two Direct Connect connections from different providers to two different AWS Direct Connect locations. They want to ensure that if one connection fails, traffic automatically fails over to the other. Which TWO steps should they take? (Select TWO.)
242A company is designing a multi-region architecture with an Application Load Balancer (ALB) in each region. They need to route traffic to the closest healthy endpoint. Which AWS service should be used for global load balancing?
243A company is using AWS Transit Gateway to connect multiple VPCs and on-premises networks. They have a VPC with a subnet that hosts a web application. They need to ensure that traffic from the on-premises network to the web application does not traverse the internet. Which TWO components are required? (Select TWO.)
244A company has a VPC with multiple subnets across three Availability Zones. They are deploying an NFS file system using Amazon EFS. They need high availability and low latency from all subnets. Which EFS deployment option meets these requirements?
245A company has a VPC with a public subnet and a private subnet. They want to allow instances in the private subnet to download patches from the internet. Which THREE components are required? (Select THREE.)
246A network engineer is troubleshooting connectivity from an EC2 instance in a private subnet to an S3 bucket. The VPC has a VPC endpoint for S3 configured. The instance can access the internet via a NAT Gateway. Which configuration is MOST likely causing the connection to S3 to fail?
247Refer to the exhibit. A VPC endpoint for S3 is created as a Gateway endpoint. The route tables rtb-11111111 and rtb-22222222 are associated with the endpoint. An EC2 instance in a subnet associated with rtb-11111111 cannot access S3 via the endpoint. What is the most likely cause?
248A company wants to establish a dedicated, private connection between their on-premises data center and AWS. They require consistent, low-latency performance and support for multiple VLANs. Which AWS service should they use?
249Refer to the exhibit. A Lambda function is attached to a VPC using the network interface eni-1234567890abcdef0. The Lambda function needs to send traffic to an on-premises server via a Direct Connect connection. The traffic is failing. Which setting on the network interface is most likely causing the issue?
250A company has a VPC with a public subnet and a private subnet. An EC2 instance in the private subnet needs to download patches from the internet. The instance is associated with a security group that allows outbound HTTPS (443) traffic. The route table for the private subnet has a default route pointing to a NAT Gateway in the public subnet. Which additional configuration is required to ensure the NAT Gateway can route the traffic?
251Refer to the exhibit. The bucket policy shown is applied to an S3 bucket. A VPC endpoint for S3 is created in a VPC with CIDR 10.0.0.0/16. An EC2 instance in the VPC tries to access an object in the bucket using the VPC endpoint. The request fails. What is the most likely reason?
252A company is running a web application on EC2 instances behind an Application Load Balancer (ALB) in a VPC. The application needs to store session state in an ElastiCache Redis cluster. The Redis cluster should not be accessible from the internet. Which network design should be used?
253A company has deployed a VPC with a public subnet and a private subnet in each of two Availability Zones. They have an Application Load Balancer (ALB) in the public subnets and EC2 instances in the private subnets. The EC2 instances need to access an external API over HTTPS. What is the MOST secure way to provide this access?
254A company is deploying a multi-tier web application in a VPC. The web tier must be accessible from the internet, while the application tier must only be accessible from the web tier. The database tier must only be accessible from the application tier. Which design best meets these requirements?
255A company has a VPC with a CIDR of 10.0.0.0/16. They have two subnets: 10.0.1.0/24 (public) and 10.0.2.0/24 (private). They launch a NAT Gateway in the public subnet and add a route in the private subnet route table: destination 0.0.0.0/0, target nat-gateway-id. An EC2 instance in the private subnet can ping an external server, but cannot connect to it via SSH. The security group allows outbound SSH (port 22), and the NACL allows outbound ephemeral ports. What is the likely cause?
256A network engineer is setting up a site-to-site VPN connection between an on-premises network and an AWS VPC. The engineer configures the customer gateway device with the correct parameters. However, the VPN tunnel status remains 'DOWN'. What is the most likely cause?
257A company is deploying a web application that will be accessed over the internet. They want to use an Application Load Balancer (ALB) to distribute traffic across EC2 instances in multiple Availability Zones. Which TWO configurations are required to make the ALB internet-facing? (Choose TWO.)
258A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network uses BGP to advertise a specific prefix (10.0.0.0/16) to AWS. The VPC CIDR is 10.0.0.0/16. The company wants to ensure that traffic from the VPC to on-premises uses the Direct Connect connection. However, traffic is going over the internet instead. What is the most likely cause?
259A company has a VPC with a CIDR of 10.0.0.0/16. They have two Availability Zones, each with a public and a private subnet. They want to connect their on-premises network (192.168.0.0/16) to the VPC using a site-to-site VPN. Which THREE resources are needed to establish the VPN connection? (Choose THREE.)
260An organization is migrating to AWS and needs to connect multiple VPCs in different AWS regions using a hub-and-spoke topology. The hub VPC will host centralized services. Which solution is most cost-effective and provides high throughput?
261A company has an AWS Direct Connect connection and wants to connect to multiple VPCs in the same region. Which TWO services can be used to achieve this? (Choose TWO.)
262A company is using a Network Load Balancer (NLB) to distribute traffic to a fleet of EC2 instances. The NLB is configured with a target group that has health checks enabled. Some instances are marked as unhealthy even though they are running and responding to requests on the health check port. What is a likely cause?
263Refer to the exhibit. A company has an S3 bucket with the bucket policy shown. An EC2 instance in a VPC with CIDR 10.0.0.0/16 tries to retrieve an object from the bucket using the S3 console, but receives an 'Access Denied' error. The instance's security group allows all outbound traffic. What is the most likely cause?
264A company has a Direct Connect connection with a private VIF to a VPC. They also have a site-to-site VPN as a backup. The on-premises network advertises the same prefix via BGP over both connections. The company wants to prefer the Direct Connect path. What configuration achieves this?
265A company has a multi-tier application deployed in a VPC. The web tier consists of an internet-facing Application Load Balancer (ALB) in public subnets, and EC2 instances in private subnets. The application tier runs on EC2 instances in separate private subnets, and the database tier uses an Amazon RDS for MySQL instance in private subnets. The application tier needs to connect to the database on port 3306. The security group for the RDS instance (sg-database) has an inbound rule allowing TCP 3306 from the security group of the application tier (sg-app). The application tier instances can connect to the database, but the web tier instances cannot. The web tier instances should not have direct database access. What is the most likely reason for the web tier's inability to connect to the database?
266A security team wants to block traffic from a specific IP address (203.0.113.5) from reaching an EC2 instance. The instance is in a public subnet with a security group that allows all traffic from the internet. A network ACL is associated with the subnet. The team adds a DENY rule for the IP in the network ACL. However, traffic from that IP still reaches the instance. What is the most likely reason?
267A company has a VPC with a CIDR of 10.0.0.0/16. They have two Availability Zones, each with 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). They have an internet-facing ALB in the public subnets and EC2 instances in the private subnets. The EC2 instances need to download updates from the internet. They deploy a NAT Gateway in each public subnet and add routes in the private subnet route tables pointing to the respective NAT Gateway in the same AZ. However, the EC2 instances in AZ2 cannot access the internet, while those in AZ1 can. What is the most likely cause?
268A company is setting up a VPC with both public and private subnets. The private subnets need outbound internet access for software updates. Which component is required to enable this?
269A network engineer is troubleshooting connectivity between an on-premises data center and a VPC over an AWS Site-to-Site VPN. The tunnel status shows UP, but traffic from on-premises to the VPC is intermittently dropped. Which TWO of the following are likely causes? (Choose 2.)
270A company uses AWS Direct Connect with a private VIF to connect to a VPC. They have an on-premises application that needs to resolve private hosted zone names in Amazon Route 53. The on-premises DNS server forwards queries for the private domain to the VPC's DNS resolver. However, resolution fails. What is the most likely cause?
271A company uses AWS Transit Gateway with multiple VPC attachments and a VPN attachment to an on-premises network. The on-premises network advertises the same prefix via two separate VPN connections for redundancy. The TGW route table shows both routes as active. Traffic from a VPC to on-premises is not load-balanced and prefers one connection. Which THREE actions would help achieve active-active load balancing? (Choose 3.)
272Which TWO of the following are valid methods to connect multiple VPCs in the same AWS region using AWS native services? (Choose two.)
273A network engineer is designing a Direct Connect solution with a public VIF and a private VIF. The private VIF will connect to a VPC via a Direct Connect Gateway. Which TWO of the following statements are correct regarding this setup? (Choose 2.)
274A media company runs a latency-sensitive streaming application on Amazon EC2 instances in a VPC. The application sends UDP traffic to multiple on-premises destinations via an AWS Transit Gateway with a VPN attachment. Users report occasional freezing. Network monitoring shows no packet loss on the VPN tunnel, but the application logs show out-of-order packets and high jitter. The company uses a single VPN tunnel with BGP dynamic routing over the public internet. The on-premises router has a 50ms latency to the AWS endpoint. The application requires low jitter and in-order delivery. What should a network engineer do to resolve the issue?
275Which THREE of the following are required to establish a highly available site-to-site VPN connection between an on-premises network and an AWS VPC? (Choose three.)
276A financial services company has a VPC with a public subnet and a private subnet. EC2 instances in the private subnet need to download patches from the internet. The company has a NAT gateway in the public subnet. The route table for the private subnet has a default route (0.0.0.0/0) pointing to the NAT gateway. However, instances cannot reach the internet. The NAT gateway is in an 'available' state and has an Elastic IP attached. The security group for the NAT gateway allows all outbound traffic. What is the most likely cause of the issue?
277Which TWO of the following are true about AWS VPC security groups? (Choose two.)
278A company has a VPC with an IPv4 CIDR block of 10.0.0.0/16. They need to connect two separate branch offices using AWS Client VPN. Each branch office has a different subnet: Branch A uses 10.0.1.0/24 and Branch B uses 10.0.2.0/24. The Client VPN endpoint is configured with a CIDR range of 10.0.3.0/24. The route table for the VPC has the local route and routes to the Client VPN endpoint. Users from both branches can connect to the VPN but cannot communicate with each other. What is the most likely reason?
279A company is deploying a new application in a VPC with public and private subnets. The application needs to access an S3 bucket in the same AWS Region. Which configuration provides the MOST secure and cost-effective connectivity?
280A 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?
281A company has deployed a web application on EC2 instances behind an Application Load Balancer (ALB) in a VPC. The application must be accessible over the internet, but the security team requires that all traffic be inspected by a third-party firewall appliance. What is the MOST scalable architecture?
282A company uses AWS Direct Connect with a private VIF to connect to a VPC. The VPC has a virtual private gateway (VGW). The on-premises network uses BGP to exchange routes with the VGW. The company wants to route traffic from the VPC to an on-premises subnet 192.168.1.0/24. The on-premises router advertises 192.168.1.0/24 over BGP. However, instances in the VPC cannot reach that subnet. The VPC route table has the local route and a route to the VGW for 0.0.0.0/0. What is the most likely cause?
283A company has a Direct Connect connection with a private VIF to a VPC. The VPC has a virtual private gateway (VGW) attached. The on-premises network advertises a prefix 10.0.0.0/8 over BGP. The VPC has subnets with CIDR 10.0.1.0/24 and 10.0.2.0/24. The company wants to ensure that traffic to on-premises uses Direct Connect. However, traffic to an S3 bucket uses the internet. What route configuration is required?
284A large enterprise uses AWS Organizations with multiple accounts. The central networking account hosts a Transit Gateway with attachments from VPCs in various accounts. The enterprise uses AWS Resource Access Manager (RAM) to share the Transit Gateway with other accounts. A network engineer in a spoke account creates a VPC and attaches it to the shared Transit Gateway. The attachment shows 'available' state. However, traffic from the spoke VPC to other attached VPCs fails. The spoke VPC route table has a route to the Transit Gateway for 0.0.0.0/0. The Transit Gateway route table has routes for the spoke VPC CIDR and other VPC CIDRs. What is the most likely cause?
285A company has multiple VPCs that need to communicate with each other using private IP addresses. The VPCs are in the same AWS account and Region. Which AWS service provides the simplest and most scalable solution?
286A company uses AWS PrivateLink to access a SaaS application hosted in another AWS account. The SaaS provider has created a VPC endpoint service in their account. The consumer has created a VPC endpoint in their VPC. The consumer's VPC has a route table with a local route and a route to a NAT gateway. The VPC endpoint is associated with a security group that allows inbound HTTPS from the consumer's VPC CIDR. The consumer's EC2 instances can resolve the DNS name of the endpoint but cannot connect to the SaaS service. What is the most likely cause?
287A company is deploying a fleet of EC2 instances in private subnets. The instances need to download patches from the internet. The company wants to minimize cost and avoid managing NAT instances. The VPC has an internet gateway (IGW) attached. What should the company do?
288A company has a VPC with public and private subnets across two Availability Zones. They have a Network Load Balancer (NLB) in the public subnets. The NLB has a target group of EC2 instances in the private subnets. The NLB is configured with TLS listeners and uses a certificate from AWS Certificate Manager (ACM). Clients connect to the NLB over the internet. Some clients report connection timeouts. The NLB access logs show that the connections are established but then hang. The target instances are healthy. The security groups for the instances allow inbound TCP/443 from the NLB's private IPs. What is the most likely cause?
289A company has a VPC with IPv4 and IPv6 CIDRs. They have a public subnet with an internet gateway and a private subnet with a NAT gateway. EC2 instances in the private subnet need to download updates from the internet. The instances have IPv6 addresses. The private subnet route table has a default route (::/0) pointing to an egress-only internet gateway. However, instances cannot reach IPv6 internet destinations. The egress-only internet gateway is attached to the VPC and in 'available' state. What is the most likely cause?
290A company is setting up a new AWS account and wants to centrally manage VPC network traffic inspection across multiple accounts using a central VPC. The company uses AWS Organizations. Which architecture meets these requirements?
291A company has a VPC with a public subnet hosting a web server. They want to make the web server accessible over the internet. The web server has a public IP address. The public subnet route table has a default route (0.0.0.0/0) to an internet gateway. The security group for the web server allows inbound HTTP (port 80) from 0.0.0.0/0. However, external users cannot access the web server. What is the most likely cause?
292A company has a VPC with an IPv4 CIDR of 10.0.0.0/16. They need to add an additional non-overlapping CIDR to the VPC. What is a valid CIDR block they can add?
293A company uses AWS Global Accelerator to improve performance for a web application hosted on EC2 instances behind an Application Load Balancer (ALB) in a VPC. The Global Accelerator has an endpoint group in the us-east-1 Region with the ALB as an endpoint. Users in Asia report high latency. The company creates a new endpoint group in ap-southeast-1 and adds the same ALB (which is still in us-east-1). However, users in Asia still experience high latency. What should the network engineer do to reduce latency for Asian users?
294A company is migrating an on-premises application to AWS. The application uses multicast for discovery. Which AWS service supports multicast traffic within a VPC?
295A company uses AWS Direct Connect with a private VIF to connect to a VPC. The VPC has a virtual private gateway (VGW). The on-premises network uses BGP to advertise routes. The company wants to ensure high availability by using two Direct Connect connections from different providers. Both connections terminate at the same Direct Connect location (same AWS device). The company configures two private VIFs, each with a separate BGP session, and attaches both to the same VGW. However, when one connection fails, traffic does not fail over. What is the most likely cause?
296A company has a Direct Connect connection with a private VIF to a VPC. The on-premises network is advertising a default route (0.0.0.0/0) over BGP. The VPC has an internet gateway attached. When an EC2 instance in the VPC sends traffic to an internet destination, which path does it take by default?
297A company is deploying a multi-tier web application on AWS. The application consists of an Application Load Balancer (ALB), a fleet of EC2 instances in an Auto Scaling group across three Availability Zones, and an Amazon RDS for MySQL database. The ALB has a target group that routes traffic to the EC2 instances on TCP port 8080. The security group for the EC2 instances allows inbound traffic from the ALB's security group on port 8080. Users report intermittent connectivity issues to the application. A network engineer reviews the VPC Flow Logs and notices that traffic from the ALB to the EC2 instances is being recorded as 'REJECT' for some requests. What is the most likely cause of this issue?
298Which TWO of the following are valid methods to connect multiple VPCs in the same AWS Region? (Choose TWO.)
299A network engineer is designing a highly available VPN connectivity between an on-premises data center and AWS. The company has two AWS Direct Connect connections terminated on two different AWS Direct Connect locations for redundancy. The company wants to use AWS Site-to-Site VPN as a backup for Direct Connect. The VPN connections will terminate on a single Virtual Private Gateway (VGW) attached to a VPC. The on-premises network has two customer gateways (CGWs) each with a unique BGP ASN. Which TWO actions should the engineer take to ensure automatic failover and load balancing? (Choose two.)
300Which THREE components are required to establish a site-to-site VPN connection between an on-premises network and AWS? (Choose THREE.)
Deep-dive questions
The most-searched questions in this domain — detailed explanations, worked examples, full answer breakdowns.
Network Implementation questions on this certification test your ability to deploy and manage network implementation concepts in scenario-based situations.
The Courseiva ANS-C01 question bank contains 300 questions in the Network Implementation domain. Click any question to see the full explanation and answer breakdown.
Start with a 10-question focused session to identify your baseline accuracy in this domain. Read every explanation — even for questions you answer correctly — to understand the reasoning. Once you score consistently above 80%, move to a 20–30 question session to confirm depth before moving to the next domain.
Yes — the session launcher on this page draws questions exclusively from the Network Implementation domain. Choose 10, 20, 30, or 50 questions for a focused session, or click individual questions to review them one by one.
Save your results, see per-domain analytics, and get readiness scores — free, for every certification.
Sign Up FreeFree forever · Every certification included