SOA-C02 Question 251
Single answerA company is hosting a web application in an AWS environment using an Auto Scaling group of EC2 instances behind an Application Load Balancer (ALB). They want to configure a custom domain name (e.g., 'app.example.com') to route traffic to the ALB. The company uses Amazon Route 53 for DNS management. How should the SysOps Administrator configure Route 53 to achieve this?
- A
Create a CNAME record in the Route 53 hosted zone for 'example.com' pointing to the ALB's DNS name.
- B
Create an A record in the Route 53 hosted zone for 'app.example.com' with an alias targeting the ALB.
- C
Create a TXT record in the Route 53 hosted zone for 'app.example.com' pointing to the ALB's DNS name.
- D
Create an SRV record in the Route 53 hosted zone for 'app.example.com' pointing to the ALB's DNS name.
Show answer and explanation
Correct answer: B
Explanation
To route traffic to an Application Load Balancer (ALB) using Amazon Route 53, the recommended approach is to create an A (alias) record. Alias records allow you to point directly to AWS resources such as an ALB and provide seamless integration with AWS services, including automatic DNS name updates when the ALB's DNS name changes. Using a CNAME, TXT, or SRV record is not appropriate for this use case.
- A. Incorrect.
This option is incorrect because a CNAME record cannot be used for the root domain (e.g., 'example.com'), and it is not the recommended approach for aliasing to an AWS resource like an ALB.
- B. Correct.
This is the correct option. Route 53 supports creating an A (alias) record to route traffic to an ALB. Alias records are recommended because they allow you to point directly to the ALB without the need to manage the ALB's DNS name manually.
- C. Incorrect.
This option is incorrect because TXT records are used for storing arbitrary text-based data, such as domain verification, not for routing traffic.
- D. Incorrect.
This option is incorrect because SRV records are used for specifying services and ports, not for routing traffic to an ALB.