Google Professional Cloud Network Engineer Question 219
Single answerGoogle Cloud PlatformYou are configuring VPC Network Peering between two VPC networks, 'VPC-A' and 'VPC-B', in your Google Cloud project. After setting up the peering connections, you discover that instances in 'VPC-A' cannot communicate with instances in 'VPC-B'. What could be the reason for this issue?
- A
The firewall rules in 'VPC-A' or 'VPC-B' do not allow traffic between the two networks.
- B
You did not enable private Google access in either 'VPC-A' or 'VPC-B'.
- C
The CIDR ranges of 'VPC-A' and 'VPC-B' overlap.
- D
You need to explicitly route traffic between 'VPC-A' and 'VPC-B' using custom routes.
Show answer and explanation
Correct answer: A
Explanation
VPC Network Peering allows private communication between two VPC networks, but it does not automatically modify firewall rules. Even after the peering connection is established, you must ensure that firewall rules in both networks permit traffic between them. Other factors like CIDR range overlap or private Google access are unrelated to the issue described.
- A. Correct.
Firewall rules need to be configured properly to allow traffic between the two networks. Even though VPC Network Peering allows connectivity, it does not automatically configure firewall rules, which could block traffic.
- B. Incorrect.
Private Google access is unrelated to VPC Network Peering. It is used to allow instances without public IP addresses to access Google APIs and services.
- C. Incorrect.
VPC Network Peering does not allow overlapping CIDR ranges. However, if the peering connection was successfully established, this is not the issue in this scenario.
- D. Incorrect.
VPC Network Peering automatically establishes routes between the two networks. There is no need to manually configure custom routes for peering to function.