Google Cloud Professional Cloud Security Engineer Practice Exam

What action must be performed to modify access to the VM running in a managed group?

1. Change its network settings

2. Modify VPC firewall rules

3. Update the VM instance itself

4. Install a dedicated API

The correct answer is: Modify VPC firewall rules

To modify access to a VM running in a managed instance group, adjusting VPC firewall rules is crucial. VPC firewall rules govern the traffic to and from instances in a Virtual Private Cloud (VPC) network. By modifying these rules, you can specifically control which IP addresses or ranges are allowed to access the VM, along with the protocols and ports that are open. For instance, if you need to allow SSH access to the VM, you would configure a firewall rule to allow inbound traffic on port 22 from specific IP addresses. Conversely, if you want to restrict access, you would modify the rules to block certain traffic patterns. Other options might seem related but do not directly result in modified access configurations for the VM. For instance, changing network settings may not sufficiently address access control on its own, and updating the VM instance itself typically pertains to changing configurations or applying patches rather than access control. Similarly, installing a dedicated API does not inherently affect access settings for the VM as that is more about extending functionality or integration capabilities rather than outright access control. Thus, modifying VPC firewall rules is the most effective and direct way to manage access to VMs in such a setup.