An existing firewall rule targets instances with the network tag web-server. You want a running VM to be affected by that rule immediately. What action is required to make the rule apply to that VM?

Adding a network tag to a running VM in Google Cloud Platform takes effect immediately without requiring a reboot or restart. Firewall rules are dynamically applied based on network tags. Therefore, simply adding the web-server tag to the VM will cause the existing firewall rule to apply to it. Stopping and restarting or recreating the VM are unnecessary and would cause downtime. Updating the VPC network to include the VM in the tag's subnet is incorrect because firewall rules apply to instances based on tags, not necessarily subnet membership in this context, and tags are applied to instances, not subnets.