You need to host a set of web servers and database servers in an AWS VPC. What would be the best practice in designing a multi-tier infrastructure?

Answer options:

A.Use a public subnet for the web tier and a public subnet for the database layer.
B.Use a public subnet for the web tier and a private subnet for the database layer.
C.Use a private subnet for the web tier and a private subnet for the database layer.
D.Use a private subnet for the web tier and a public subnet for the database layer.

Correct Answer – B
The ideal setup ensures that the web server is hosted in the public subnet so that users on the internet can access it. The database server can be hosted in the private subnet.
The below diagram from AWS Documentation shows how this can be set up.
For more information on public and private subnets in AWS, please visit the following URL-
https://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_Scenario2.html