200-901 Question 188
Select 3A company has deployed a web application that communicates with a backend database. The application runs on multiple servers behind a load balancer, and the database is hosted on a separate server. The network team wants to configure firewall rules to ensure secure communication. Which of the following firewall rules should be configured to allow the application to function correctly?
- A
Allow inbound traffic to the load balancer on port 80 and 443
- B
Allow inbound traffic to the database server on port 3306
- C
Allow outbound traffic from the application servers to the database server on port 3306
- D
Allow inbound traffic to the application servers on port 22 for SSH access
- E
Allow inbound traffic to the load balancer on port 25 for SMTP
Show answer and explanation
Correct answers: A, B, C
Explanation
To ensure the application functions correctly, the firewall must allow web traffic (ports 80 and 443) to the load balancer and database communication (port 3306) between the application servers and the database. SSH and SMTP traffic are unrelated to the application's core functionality and are not required in this scenario.
- A. Correct.
Correct: HTTP and HTTPS traffic (ports 80 and 443) need to be allowed to the load balancer for the application to be reachable by users.
- B. Correct.
Correct: Port 3306 is the default port for MySQL databases, and access must be allowed for the application to communicate with the database server.
- C. Correct.
Correct: The application servers need to establish outbound connections to the database server on port 3306 for database queries.
- D. Incorrect.
Incorrect: While SSH (port 22) may be required for administrative tasks, it is not relevant to the application’s functionality in this scenario.
- E. Incorrect.
Incorrect: SMTP (port 25) is used for email services and is not relevant to the web application or database communication.