200-901 Question 189
Select 2A company is hosting a web application that uses a load balancer to distribute traffic across multiple backend servers. The application needs to allow HTTPS traffic from external clients, and it must communicate with a backend API service over HTTP. Which of the following port configurations must be allowed through the firewall to ensure proper functionality?
- A
Port 80 for HTTP traffic to the backend API
- B
Port 443 for HTTPS traffic from external clients
- C
Port 22 for SSH management of backend servers
- D
Port 3306 for MySQL database communication
- E
Port 8080 for backend API communication if it uses a custom port
Show answer and explanation
Correct answers: A, B
Explanation
To ensure proper functionality, the firewall must allow port 443 for external HTTPS traffic as it secures communication to the web application. Additionally, port 80 may be required if the backend API service communicates over HTTP. Other ports, such as SSH or database communication, are not relevant to the described scenario unless explicitly mentioned.
- A. Correct.
Port 80 is used for HTTP traffic, but in this scenario, HTTPS (port 443) is required for external clients. Therefore, this is not correct.
- B. Correct.
Port 443 is required for HTTPS traffic from external clients to the web application. This is correct for secure communication.
- C. Incorrect.
Port 22 is used for SSH management, but there is no mention in the scenario that SSH access is required for the application's functionality. This is not correct.
- D. Incorrect.
Port 3306 is used for MySQL database communication. However, there is no indication in the scenario that the application communicates with a MySQL database. This is not correct.
- E. Incorrect.
Port 8080 would only be required if the backend API explicitly used this custom port. Since there is no mention of a custom port, this is not correct.