Last Updated on October 3, 2021 by Admin 2

SOA-C01 : AWS-SysOps ​​​​​: Part 01

  1. You are currently hosting multiple applications in a VPC and have logged numerous port scans coming in from a specific IP address block. Your security team has requested that all access from the offending IP address block be denied for the next 24 hours.

    Which of the following is the best method to quickly and temporarily deny access from the specified IP address block?

    • Create an AD policy to modify Windows Firewall settings on all hosts in the VPC to deny access from the IP address block
    • Modify the Network ACLs associated with all public subnets in the VPC to deny access from the IP address block
    • Add a rule to all of the VPC 5 Security Groups to deny access from the IP address block
    • Modify the Windows Firewall settings on all Amazon Machine Images (AMIs) that your organization uses in that VPC to deny access from the IP address block
  2. When preparing for a compliance assessment of your system built inside of AWS. what are three best-practices for you to prepare for an audit? (Choose three.)

    • Gather evidence of your IT operational controls
    • Request and obtain applicable third-party audited AWS compliance reports and certifications
    • Request and obtain a compliance and security tour of an AWS data center for a pre-assessment security review
    • Request and obtain approval from AWS to perform relevant network scans and in-depth penetration tests of your system’s Instances and endpoints
    • Schedule meetings with AWS’s third-party auditors to provide evidence of AWS compliance that maps to your control objectives
  3. You have started a new job and are reviewing your company’s infrastructure on AWS You notice one web application where they have an Elastic Load Balancer (&B) in front of web instances in an Auto Scaling Group When you check the metrics for the ELB in CloudWatch you see four healthy instances in Availability Zone (AZ) A and zero in AZ B There are zero unhealthy instances.

    What do you need to fix to balance the instances across AZs?

    • Set the ELB to only be attached to another AZ
    • Make sure Auto Scaling is configured to launch in both AZs
    • Make sure your AMI is available in both AZs
    • Make sure the maximum size of the Auto Scaling Group is greater than 4
  4. You have been asked to leverage Amazon VPC BC2 and SOS to implement an application that submits and receives millions of messages per second to a message queue. You want to ensure your application has sufficient bandwidth between your EC2 instances and SQS.

    Which option will provide the most scalable solution for communicating between the application and SQS?

    • Ensure the application instances are properly configured with an Elastic Load Balancer
    • Ensure the application instances are launched in private subnets with the EBS-optimized option enabled
    • Ensure the application instances are launched in public subnets with the associate-public-IP-address=true option enabled
    • Launch application instances in private subnets with an Auto Scaling group and Auto Scaling triggers configured to watch the SQS queue size
  5. You have identified network throughput as a bottleneck on your m1.small EC2 instance when uploading data Into Amazon S3 In the same region.

    How do you remedy this situation?

    • Add an additional ENI
    • Change to a larger Instance
    • Use DirectConnect between EC2 and S3
    • Use EBS PIOPS on the local volume
  6. When attached to an Amazon VPC, which two components provide connectivity with external networks? (Choose two.)

    • Elastic IPS (EIP)
    • NAT Gateway (NAT)
    • Internet Gateway {IGW)
    • Virtual Private Gateway (VGW)
  7. Your application currently leverages AWS Auto Scaling to grow and shrink as load Increases/ decreases and has been performing well. Your marketing team expects a steady ramp up in traffic to follow an upcoming campaign that will result in a 20x growth in traffic over 4 weeks. Your forecast for the approximate number of Amazon EC2 instances necessary to meet the peak demand is 175.

    What should you do to avoid potential service disruptions during the ramp up in traffic?

    • Ensure that you have pre-allocated 175 Elastic IP addresses so that each server will be able to obtain one as it launches
    • Check the service limits in Trusted Advisor and adjust as necessary so the forecasted count remains within limits.
    • Change your Auto Scaling configuration to set a desired capacity of 175 prior to the launch of the marketing campaign
    • Pre-warm your Elastic Load Balancer to match the requests per second anticipated during peak demand prior to the marketing campaign
    Explanation:
    Amazon ELB is able to handle the vast majority of use cases for our customers without requiring “pre-warming” (configuring the load balancer to have the appropriate level of capacity based on
    expected traffic).
  8. You have an Auto Scaling group associated with an Elastic Load Balancer (ELB). You have noticed that instances launched via the Auto Scaling group are being marked unhealthy due to an ELB health check, but these unhealthy instances are not being terminated.

    What do you need to do to ensure trial instances marked unhealthy by the ELB will be terminated and replaced?

    • Change the thresholds set on the Auto Scaling group health check
    • Add an Elastic Load Balancing health check to your Auto Scaling group
    • Increase the value for the Health check interval set on the Elastic Load Balancer
    • Change the health check set on the Elastic Load Balancer to use TCP rather than HTTP checks
  9. Which two AWS services provide out-of-the-box user configurable automatic backup-as-a-service and backup rotation options? (Choose two.)

    • Amazon S3
    • Amazon RDS
    • Amazon EBS
    • Amazon Red shift
    Explanation:

    By default, and at no additional charge, Amazon RDS enables automated backups of your DB Instance with a 1-day retention period.
    By default, Amazon Redshift enables automated backups of your data warehouse cluster with a 1-day retention period.

  10. An organization has configured a VPC with an Internet Gateway (IGW). pairs of public and private subnets (each with one subnet per Availability Zone), and an Elastic Load Balancer (ELB) configured to use the public subnets. The application s web tier leverages the ELB. Auto Scaling and a mum-AZ RDS database instance The organization would like to eliminate any potential single points ft failure in this design.

    What step should you take to achieve this organization’s objective?

    • Nothing, there are no single points of failure in this architecture.
    • Create and attach a second IGW to provide redundant internet connectivity.
    • Create and configure a second Elastic Load Balancer to provide a redundant load balancer.
    • Create a second multi-AZ RDS instance in another Availability Zone and configure replication to provide a redundant database.
    Explanation:

    You need multiple ELB if you want HA across regions.
    “AWS Load Balancer –Cross Network
    Many times it happens that after setting up your ELB, you experience significant drops in your performance. The best way to handle this situation is to start with identifying whether your ELB is single AZ or multiple AZ, as single AZ ELB is also considered as one of the Single Points of Failures on AWS Cloud. Once you identify your ELB, it is necessary to make sure ELB loads are kept cross regions.

  11. Which of the following are characteristics of Amazon VPC subnets? (Choose two.)

    • Each subnet maps to a single Availability Zone
    • A CIDR block mask of /25 is the smallest range supported
    • Instances in a private subnet can communicate with the internet only if they have an Elastic IP.
    • By default, all subnets can route between each other, whether they are private or public
    • V Each subnet spans at least 2 Availability zones to provide a high-availability environment
    Explanation

    “Each subnet must reside entirely within one Availability Zone and cannot span zones.”
    “Every subnet that you create is automatically associated with the main route table for the VPC.”
    You are creating an Auto Scaling group whose Instances need to insert a custom metric into CloudWatch.

  12. Which method would be the best way to authenticate your CloudWatch PUT request?

    • Create an IAM role with the Put MetricData permission and modify the Auto Scaling launch configuration to launch instances in that role
    • Create an IAM user with the PutMetricData permission and modify the Auto Scaling launch configuration to inject the userscredentials into the instance User Data
    • Modify the appropriate Cloud Watch metric policies to allow the Put MetricData permission to instances from the Auto Scaling group
    • Create an IAM user with the PutMetricData permission and put the credentials in a private repository and have applications on the server pull the credentials as needed
    Explanation:
    Creates an IAM role is always the best practice to give permissions to EC2 instances in order to interact with other AWS services
  13. When an EC2 instance that is backed by an S3-based AMI Is terminated, what happens to the data on me root volume?

    • Data is automatically saved as an E8S volume.
    • Data is automatically saved as an ESS snapshot.
    • Data is automatically deleted.
    • Data is unavailable until the instance is restarted.
  14. You have a web application leveraging an Elastic Load Balancer (ELB) In front of the web servers deployed using an Auto Scaling Group Your database is running on Relational Database Service (RDS) The application serves out technical articles and responses to them in general there are more views of an article than there are responses to the article. On occasion, an article on the site becomes extremely popular resulting in significant traffic Increases that causes the site to go down.

    What could you do to help alleviate the pressure on the infrastructure while maintaining availability during these events? (Choose three.)

    • Leverage CloudFront for the delivery of the articles.
    • Add RDS read-replicas for the read traffic going to your relational database
    • Leverage ElastiCache for caching the most frequently used data.
    • Use SOS to queue up the requests for the technical posts and deliver them out of the queue.
    • Use Route53 health checks to fail over to an S3 bucket for an error page.
  15. The majority of your Infrastructure is on premises and you have a small footprint on AWS Your company has decided to roll out a new application that is heavily dependent on low latency connectivity to LOAP for authentication Your security policy requires minimal changes to the company’s existing application user management processes.

    What option would you implement to successfully launch this application1?

    • Create a second, independent LOAP server in AWS for your application to use for authentication
    • Establish a VPN connection so your applications can authenticate against your existing on-premises LDAP servers
    • Establish a VPN connection between your data center and AWS create a LDAP replica on AWS and configure your application to use the LDAP replica for authentication
    • Create a second LDAP domain on AWS establish a VPN connection to establish a trust relationship between your new and existing domains and use the new domain for authentication
    Explanation:
    Create read replica(RODC) of main LDAP server so that LDAP read replica or RODC can authenticate with application locally.
    Creating new domain and trust relationship would require lot of work and changes in exiting ldap configuration so D cannot be answer here.
  16. You need to design a VPC for a web-application consisting of an Elastic Load Balancer (ELB). a fleet of web/application servers, and an RDS database. The entire Infrastructure must be distributed over 2 availability zones.

    Which VPC configuration works while assuring the database is not available from the Internet?

    • One public subnet for ELB one public subnet for the web-servers, and one private subnet for the database
    • One public subnet for ELB two private subnets for the web-servers, two private subnets for RDS
    • Two public subnets for ELB two private subnets for the web-servers and two private subnets for RDS
    • Two public subnets for ELB two public subnets for the web-servers, and two public subnets for RDS
    Explanation:

    While using ELB for web applications, ensure that you place all other EC2 instances in private subnets wherever possible. Except where there is an explicit requirement for instances requiring outside world access and Elastic IP attached, place all the instances in private subnets only. In the Amazon VPC environment, only ELBs must be in the public subnet as secure practice.
    You will need to select a Subnet for each Availability Zone where you wish traffic to be routed by your load balancer. If you have instances in only one Availability Zone, please select at least two Subnets in different Availability Zones to provide higher availability for your load balance

  17. An application that you are managing has EC2 instances & Dynamo OB tables deployed to several AWS Regions in order to monitor the performance of the application globally, you would like to see two graphs:

    1) Avg CPU Utilization across all EC2 instances
    2) Number of Throttled Requests for all DynamoDB tables.

    How can you accomplish this?

    • Tag your resources with the application name, and select the tag name as the dimension in the Cloudwatch Management console to view the respective graphs
    • Use the Cloud Watch CLI tools to pull the respective metrics from each regional endpoint Aggregate the data offline & store it for graphing in CloudWatch.
    • Add SNMP traps to each instance and DynamoDB table Leverage a central monitoring server to capture data from each instance and table Put the aggregate data into Cloud Watch for graphing.
    • Add a CloudWatch agent to each instance and attach one to each DynamoDB table. When configuring the agent set the appropriate application name & view the graphs in CloudWatch.
  18. When assessing an organization s use of AWS API access credentials which of the following three credentials should be evaluated? (Choose three.)

    • Key pairs
    • Console passwords
    • Access keys
    • Signing certificates
    • Security Group memberships
  19. You have a Linux EC2 web server instance running inside a VPC The instance is In a public subnet and has an EIP associated with it so you can connect to It over the Internet via HTTP or SSH The instance was also fully accessible when you last logged in via SSH. and was also serving web requests on port 80.

    Now you are not able to SSH into the host nor does it respond to web requests on port 80 that were working fine last time you checked You have double-checked that all networking configuration parameters (security groups route tables. IGW’EIP. NACLs etc) are properly configured {and you haven’t made any changes to those anyway since you were last able to reach the Instance). You look at the EC2 console and notice that system status check shows “impaired.”

    Which should be your next step in troubleshooting and attempting to get the instance back to a healthy state so that you can log in again?

    • Stop and start the instance so that it will be able to be redeployed on a healthy host system that most likely will fix the “impaired” system status
    • Reboot your instance so that the operating system will have a chance to boot in a clean healthy state that most likely will fix the ‘impaired” system status
    • Add another dynamic private IP address to me instance and try to connect via mat new path, since the networking stack of the OS may be locked up causing the “impaired” system status.
    • Add another Elastic Network Interface to the instance and try to connect via that new path since the networking stack of the OS may be locked up causing the “impaired” system status
    • un-map and then re-map the EIP to the instance, since the IGWVNAT gateway may not be working properly, causing the “impaired” system status
  20. What is a placement group?

    • A collection of Auto Scaling groups in the same Region
    • Feature that enables EC2 instances to interact with each other via nigh bandwidth, low latency connections
    • A collection of Elastic Load Balancers in the same Region or Availability Zone
    • A collection of authorized Cloud Front edge locations for a distribution