Which of the following statement is correct?

You are working with a user to set up an application in a new VPC behind a firewall and it is noticed that the user is concerned about data egress. Therefore, to provide assistance you want to configure the fewest open egress ports .

Which of the following statement is correct?
A . Set up a high-priority (1000) rule that blocks all egress and a low-priority (65534) rule that allows only the appropriate ports.
B . Set up a low-priority (65534) rule that blocks all egress and a high-priority rule (1000) that allows only the appropriate ports.
C . Set up a high-priority (1000) rule to allow the appropriate ports.
D . Set up a high-priority (1000) rule that pairs both ingress and egress ports.

View Answer

Answer: B

Explanation:

Implied rules Every VPC network has two implied firewall rules. These rules exist, but are not shown in the Cloud Console:

Implied allow egress rule. An egress rule whose action is allow, destination is 0.0.0.0/0, and priority is the lowest possible (65535) lets any instance send traffic to any destination, except for traffic blocked by Google Cloud. A higher priority firewall rule may restrict outbound access. Internet access is allowed if no other firewall rules deny outbound traffic and if the instance has an external IP address or uses a Cloud NAT instance. For more information, see Internet access requirements.

Reference link- https://cloud.google.com/vpc/docs/firewalls