171. A company has stateful security appliances that are deployed to multiple Availability Zones in a centralized shared services VPC. The AWS environment includes a transit gateway that is attached to application VPCs and the shared services VPC. The application VPCs have workloads that are deployed in private subnets across multiple Availability Zones. The stateful appliances in the shared services VPC inspect all east west (VPC-to-VPC) traffic.
Users report that inter-VPC traffic to different Availability Zones is dropping. A network engineer verified this claim by issuing Internet Control Message Protocol (ICMP) pings between workloads in different Availability Zones across the application VPCs. The network engineer has ruled out security groups, stateful device configurations and network ACLs as the cause of the dropped traffic.
What is causing the traffic to drop?
A. The stateful appliances and the transit gateway attachments are deployed in a separate subnet in the shared services VPC.
B. Appliance mode is not enabled on the transit gateway attachment to the shared services VPC.
C. The stateful appliances and the transit gateway attachments are deployed in the same subnet in the shared services VPC.
D. Appliance mode is not enabled on the transit gateway attachment to the application VPCs.
Answer
B
172. A company has hundreds of Amazon EC2 instances that are running in two production VPCs across all Availability Zones in the us-east-1 Region. The production VPCs are named
VPC A and VPC B.
A new security regulation requires all traffic between production VPCs to be inspected before the traffic is routed to its final destination. The company deploys a new shared VPC that contains a stateful firewall appliance and a transit gateway with a VPC attachment across all VPCs to route traffic between VPC A and VPC B through the firewall appliance for inspection. During testing, the company notices that the transit gateway is dropping the traffic whenever the traffic is between two Availability Zones.
What should a network engineer do to fix this issue with the LEAST management overhead?
A. In the shared VPC, replace the VPC attachment with a VPN attachment. Create a VPN tunnel between the transit gateway and the firewall appliance. Configure BGP.
B. Enable transit gateway appliance mode on the VPC attachment in VPC A and VPC B.
C. Enable transit gateway appliance mode on the VPC attachment in the shared VPC.
D. In the shared VPC, configure one VPC peering connection to VPC A and another VPC peering connection to VPC B.
Answer
C
173. A company has deployed a critical application on a fleet of Amazon EC2 instances behind an Application Load Balancer. The application must always be reachable on port 443 from the public internet. The application recently had an outage that resulted from an incorrect change to the EC2 security group.
A network engineer needs to automate a way to verify the network connectivity between the public internet and the EC2 instances whenever a change is made to the security group. The solution also must notify the network engineer when the change affects the connection.
Which solution will meet these requirements?
A. Enable VPC Flow Logs on the elastic network interface of each EC2 instance to capture REJECT traffic on port 443. Publish the flow log records to a log group in Amazon CloudWatch Logs. Create a CloudWatch Logs metric filter for the log group for rejected traffic. Create an alarm to notify the network engineer.
B. Enable VPC Flow Logs on the elastic network interface of each EC2 instance to capture all traffic on port 443. Publish the flow log records to a log group in Amazon CloudWatch Logs. Create a CloudWatch Logs metric filter for the log group for all traffic. Create an alarm to notify the network engineer
C. Create a VPC Reachability Analyzer path on port 443. Specify the security group as the source. Specify the EC2 instances as the destination. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the network engineer when a change to the security group affects the connection. Create an AWS Lambda function to start Reachability Analyzer and to publish a message to the SNS topic in case the analyses fail Create an Amazon EventBridge (Amazon CloudWatch Events) rule to invoke the Lambda function when a change to the security group occurs.
D. Create a VPC Reachability Analyzer path on port 443. Specify the internet gateway of the VPC as the source. Specify the EC2 instances as the destination. Create an Amazon Simple Notification Service (Amazon SNS) topic to notify the network engineer when a change to the security group affects the connection. Create an AWS Lambda function to start Reachability Analyzer and to publish a message to the SNS topic in case the analyses fail. Create an Amazon EventBridge (Amazon CloudWatch Events) rule to invoke the Lambda function when a change to the security group occurs.
Answer
D
174. A security team is performing an audit of a company’s AWS deployment. The security team is concerned that two applications might be accessing resources that should be blocked by network ACLs and security groups. The applications are deployed across two Amazon Elastic Kubernetes Service (Amazon EKS) clusters that use the Amazon VPC Container Network Interface (CNI) plugin for Kubernetes. The clusters are in separate subnets within the same VPC and have a Cluster Autoscaler configured.
The security team needs to determine which POD IP addresses are communicating with which services throughout the VPC. The security team wants to limit the number of flow logs and wants to examine the traffic from only the two applications.
Which solution will meet these requirements with the LEAST operational overhead?
A. Create VPC flow logs in the default format. Create a filter to gather flow logs only from the EKS nodes. Include the srcaddr field and the dstaddr field in the flow logs.
B. Create VPC flow logs in a custom format. Set the EKS nodes as the resource Include the pkt-srcaddr field and the pkt-dstaddr field in the flow logs.
C. Create VPC flow logs in a custom format. Set the application subnets as resources. Include the pkt-srcaddr field and the pkt-dstaddr field in the flow logs.
D. Create VPC flow logs in a custom format. Create a filter to gather flow logs only from the EKS nodes. Include the pkt-srcaddr field and the pkt-dstaddr field in the flow logs.
Answer
C
175. A data analytics company has a 100-node high performance computing (HPC) cluster. The HPC cluster is for parallel data processing and is hosted in a VPC in the AWS Cloud. As part of the data processing workflow, the HPC cluster needs to perform several DNS queries to resolve and connect to Amazon RDS databases, Amazon S3 buckets, and on-premises data stores that are accessible through AWS Direct Connect. The HPC cluster can increase in size by five to seven times during the company’s peak event at the end of the year.
The company is using two Amazon EC2 instances as primary DNS servers for the VPC. The EC2 instances are configured to forward queries to the default VPC resolver for Amazon Route 53 hosted domains and to the on-premises DNS servers for other on-premises hosted domain names. The company notices job failures and finds that DNS queries from the HPC cluster nodes failed when the nodes tried to resolve RDS and S3 bucket endpoints.
Which architectural change should a network engineer implement to provide the DNS service in the MOST scalable way?
A. Scale out the DNS service by adding two additional EC2 instances in the VPC. Reconfigure half of the HPC cluster nodes to use these new DNS servers. Plan to scale out by adding additional EC2 instance-based DNS servers in the future as the HPC cluster size grows.
B. Scale up the existing EC2 instances that the company is using as DNS servers. Change the instance size to the largest possible instance size to accommodate the current DNS load and the anticipated load in the future.
C. Create Route 53 Resolver outbound endpoints. Create Route 53 Resolver rules to forward queries to on-premises DNS servers for on premises hosted domain names. Reconfigure the HPC cluster nodes to use the default VPC resolver instead of the EC2 instance-based DNS servers. Terminate the EC2 instances.
D. Create Route 53 Resolver inbound endpoints. Create rules on the on-premises DNS servers to forward queries to the default VPC resolver. Reconfigure the HPC cluster nodes to forward all DNS queries to the on-premises DNS servers. Terminate the EC2 instances.
Answer
C
176. A company’s network engineer is designing an active-passive connection to AWS from two on-premises data centers. The company has set up AWS Direct Connect connections between the on-premises data centers and AWS. From each location, the company is using a transit VIF that connects to a Direct Connect gateway that is associated with a transit gateway.
The network engineer must ensure that traffic from AWS to the data centers is routed first to the primary data center. The traffic should be routed to the failover data center only in the case of an outage.
Which solution will meet these requirements?
A. Set the BGP community tag for all prefixes from the primary data center to 7224:7100. Set the BGP community tag for all prefixes from the failover data center to 7224:7300
B. Set the BGP community tag for all prefixes from the primary data center to 7224:7300. Set the BGP community tag for all prefixes from the failover data center to 7224:7100
C. Set the BGP community tag for all prefixes from the primary data center to 7224:9300. Set the BGP community tag for all prefixes from the failover data center to 7224:9100
D. Set the BGP community tag for all prefixes from the primary data center to 7224:9100. Set the BGP community tag for all prefixes from the failover data center to 7224:9300
Answer
B
177. A real estate company is building an internal application so that real estate agents can upload photos and videos of various properties. The application will store these photos and videos in an Amazon S3 bucket as objects and will use Amazon DynamoDB to store corresponding metadata. The S3 bucket will be configured to publish all PUT events for new object uploads to an Amazon Simple Queue Service (Amazon SQS) queue.
A compute cluster of Amazon EC2 instances will poll the SQS queue to find out about newly uploaded objects. The cluster will retrieve new objects, perform proprietary image and video recognition and classification update metadata in DynamoDB and replace the objects with new watermarked objects. The company does not want public IP addresses on the EC2 instances.
Which networking design solution will meet these requirements MOST cost-effectively as application usage increases?
A. Place the EC2 instances in a public subnet. Disable the Auto-assign Public IP option while launching the EC2 instances. Create an internet gateway. Attach the internet gateway to the VPC. In the public subnet’s route table, add a default route that points to the internet gateway.
B. Place the EC2 instances in a private subnet. Create a NAT gateway in a public subnet in the same Availability Zone. Create an internet gateway. Attach the internet gateway to the VPC. In the public subnet’s route table, add a default route that points to the internet gateway
C. Place the EC2 instances in a private subnet. Create an interface VPC endpoint for Amazon SQS. Create gateway VPC endpoints for Amazon S3 and DynamoDB.
D. Place the EC2 instances in a private subnet. Create a gateway VPC endpoint for Amazon SQS. Create interface VPC endpoints for Amazon S3 and DynamoDB.
Answer
C
178. A company has an AWS Direct Connect connection between its on-premises data center in the United States (US) and workloads in the us-east-1 Region. The connection uses a transit VIF to connect the data center to a transit gateway in us-east-1.
The company is opening a new office in Europe with a new on-premises data center in England. A Direct Connect connection will connect the new data center with some workloads that are running in a single VPC in the eu-west-2 Region. The company needs to connect the US data center and us-east-1 with the Europe data center and eu-west-2. A network engineer must establish full connectivity between the data centers and Regions with the lowest possible latency.
How should the network engineer design the network architecture to meet these requirements?
A. Connect the VPC in eu-west-2 with the Europe data center by using a Direct Connect gateway and a private VIF. Associate the transit gateway in us-east-1 with the same Direct Connect gateway. Enable SiteLink for the transit VIF and the private VIF.
B. Connect the VPC in eu-west-2 to a new transit gateway. Connect the Europe data center to the new transit gateway by using a Direct Connect gateway and a new transit VIF. Associate the transit gateway in us-east-1 with the same Direct Connect gateway. Enable SiteLink for both transit VIFs. Peer the two transit gateways.
C. Connect the VPC in eu-west-2 to a new transit gateway. Connect the Europe data center to the new transit gateway by using a Direct Connect gateway and a new transit VIF. Create a new Direct Connect gateway. Associate the transit gateway in us-east-1 with the new Direct Connect gateway. Enable SiteLink for both transit VIFs. Peer the two transit gateways.
D. Connect the VPC in eu-west-2 with the Europe data center by using a Direct Connect gateway and a private VIF. Create a new Direct Connect gateway. Associate the transit gateway in us-east-1 with the new Direct Connect gateway. Enable SiteLink for the transit VIF and the private VIF.
Answer
B
179. A network engineer has deployed an Amazon EC2 instance in a private subnet in a VPC. The VPC has no public subnet. The EC2 instance hosts application code that sends messages to an Amazon Simple Queue Service (Amazon SQS) queue. The subnet has the default network ACL with no modification applied. The EC2 instance has the default security group with no modification applied.
The SQS queue is not receiving messages.
Which of the following are possible causes of this problem? (Choose two.)
A. The EC2 instance is not attached to an IAM role that allows write operations to Amazon SQS.
B. The security group is blocking traffic to the IP address range used by Amazon SQS
C. There is no interface VPC endpoint configured for Amazon SQS
D. The network ACL is blocking return traffic from Amazon SQS
E. There is no route configured in the subnet route table for the IP address range used by Amazon SQS
Answer
A, C
180. A network engineer needs to standardize a company’s approach to centralizing and managing interface VPC endpoints for private communication with AWS services. The company uses AWS Transit Gateway for inter-VPC connectivity between AWS accounts through a hub-and-spoke model. The company’s network services team must manage all Amazon Route 53 zones and interface endpoints within a shared services AWS account. The company wants to use this centralized model to provide AWS resources with access to AWS Key Management Service (AWS KMS) without sending traffic over the public internet.
What should the network engineer do to meet these requirements?
A. In the shared services account, create an interface endpoint for AWS KMS. Modify the interface endpoint by disabling the private DNS name. Create a private hosted zone in the shared services account with an alias record that points to the interface endpoint. Associate the private hosted zone with the spoke VPCs in each AWS account.
B. In the shared services account, create an interface endpoint for AWS KMS. Modify the interface endpoint by disabling the private DNS name. Create a private hosted zone in each spoke AWS account with an alias record that points to the interface endpoint. Associate each private hosted zone with the shared services AWS account.
C. In each spoke AWS account, create an interface endpoint for AWS KMS. Modify each interface endpoint by disabling the private DNS name. Create a private hosted zone in each spoke AWS account with an alias record that points to each interface endpoint. Associate each private hosted zone with the shared services AWS account.
D. In each spoke AWS account, create an interface endpoint for AWS KMS. Modify each interface endpoint by disabling the private DNS name. Create a private hosted zone in the shared services account with an alias record that points to each interface endpoint. Associate the private hosted zone with the spoke VPCs in each AWS account.
Answer
A