Google Professional Cloud Network Engineer Question 575
Single answerGoogle Cloud PlatformYou are designing a Google Cloud networking solution to allow a private Compute Engine instance to access external services on the internet. You decide to use Cloud NAT for this purpose. Your solution needs to ensure that the instance uses specific IP addresses for outbound traffic. How should you configure the NAT IP address allocation to meet this requirement?
- A
Use automatic NAT IP address allocation to let Google Cloud assign IP addresses dynamically.
- B
Manually reserve static external IP addresses and assign them to the NAT configuration.
- C
Enable IP masquerading on the Compute Engine instance and let it use the VPC network's default internet gateway.
- D
Attach a public IP address directly to the Compute Engine instance to route outbound traffic.
Show answer and explanation
Correct answer: B
Explanation
To meet the requirement of ensuring that the Compute Engine instance uses specific IPs for outbound traffic, you must manually reserve static external IP addresses and assign them to the Cloud NAT configuration. This provides control over the IP addresses used, which is not possible with automatic NAT IP allocation or other methods like IP masquerading or directly attaching public IPs.
- A. Incorrect.
Automatic NAT IP address allocation allows Google Cloud to dynamically manage NAT IPs, but this does not guarantee specific IP addresses for outbound traffic.
- B. Correct.
Manually reserving static external IP addresses and assigning them to the NAT configuration ensures that the instance uses specific IPs for outbound traffic, meeting the requirement.
- C. Incorrect.
IP masquerading does not allow you to specify static IPs for outbound traffic. It simply hides the internal IPs behind the VPC network's external IP (if one exists).
- D. Incorrect.
Attaching a public IP address directly to the instance exposes it to the internet, which is against the requirement of using Cloud NAT for outbound traffic.