Google Professional Cloud Network Engineer Question 557
Single answerGoogle Cloud PlatformYour company has deployed an application that is accessible both internally from the corporate network and externally over the internet. The application uses the same domain name, 'app.example.com', but internal users should resolve the domain to an internal IP address (10.1.1.5), while external users should resolve it to a public IP address (35.199.128.10). Which approach should you take to configure DNS resolution while maintaining security and performance?
- A
Use Google Cloud DNS policies to set up a single public DNS zone and configure it to resolve to both the internal and external IPs.
- B
Use split-horizon DNS by creating a private DNS zone for internal resolution and a public DNS zone for external resolution.
- C
Use a single public DNS zone and configure conditional forwarding to resolve internal IP addresses for users inside the corporate network.
- D
Use a Cloud Load Balancer with a single backend service that dynamically directs traffic to internal or external IPs based on user location.
Show answer and explanation
Correct answer: B
Explanation
Split-horizon DNS is a technique in which separate DNS zones are created to manage internal and external DNS resolution for the same domain. In this case, creating a private DNS zone for internal users and a public DNS zone for external users ensures that 'app.example.com' resolves to the internal IP address (10.1.1.5) for corporate users and the public IP address (35.199.128.10) for external users. This approach ensures security, performance, and proper DNS resolution for both internal and external users.
- A. Incorrect.
Google Cloud DNS policies do not allow you to configure a single DNS zone to resolve to different IPs based on the user's location (internal vs. external). This option is incorrect.
- B. Correct.
Split-horizon DNS is the correct approach here. By creating a private DNS zone for internal users and a public DNS zone for external users, you can ensure that 'app.example.com' resolves to the correct IP address depending on whether the user is internal or external.
- C. Incorrect.
Conditional forwarding is not an appropriate solution in this scenario, as it does not align with best practices for managing DNS resolution in Google Cloud and does not provide a straightforward way to maintain separate IPs for internal and external users.
- D. Incorrect.
A Cloud Load Balancer does not manage DNS resolution and cannot serve different IP addresses for the same domain based on user location. It is used for traffic distribution rather than DNS configuration.