Google Updated Professional-Cloud-Security-Engineer Exam Questions and Answers by caelan

To ensure that a Compute Engine instance does not have access to the internet or to any Google APIs or services, you need to disable the following settings:

Public IP: Disabling the public IP address ensures that the instance does not have a direct connection to the internet. Without a public IP address, the instance cannot be accessed from or communicate with the internet directly.

Private Google Access: Disabling Private Google Access ensures that the instance does not have access to Google APIs and services through the internal Google network. Private Google Access allows instances without a public IP to reach Google APIs and services using private IP addresses, but disabling it will block this path.

Disabling these settings will effectively isolate the instance from both the public internet and Google's internal API services.

References

Google Cloud VPC Documentation - Overview

Configuring Private Google Access

Compute Engine Network Overview

Google Cloud Armor helps to protect applications from DDoS attacks and web application firewall (WAF) threats like XSS and SQLi. To use Google Cloud Armor security policies, certain requirements must be met:

External Load Balancers: Google Cloud Armor is specifically designed to work with external HTTP(S) load balancers, which handle traffic at the edge of the Google Cloud network. This type of load balancer provides a global frontend that can distribute traffic to various backends.

Load Balancing Scheme: The backend service associated with the Google Cloud Armor policy must have an EXTERNAL load balancing scheme. This scheme allows the service to accept traffic from outside the Google Cloud network, which is necessary for applying security policies effectively at the network edge.

These requirements ensure that Google Cloud Armor can inspect and filter incoming traffic before it reaches your web application's backend services, providing an additional layer of security against common web vulnerabilities.

References

Google Cloud Armor Documentation

External HTTP(S) Load Balancing Overview

The core requirement is to grant temporary, external users access to your Google Cloud environment while ensuring access control remains managed by their employer's identity provider (IdP). This allows your organization to follow the principle of least privilege and ensures access is revoked automatically when the user leaves the partner company (or is removed from the partner's IdP).

Workforce Identity Federation is the service specifically designed for granting external identities (partners, vendors, customers) access to Google Cloud resources without needing to sync or create managed Google accounts for them.

Extracts:

"Workforce Identity Federation is designed for the scenario where a partner organization needs to access your Google Cloud resources... it lets you use an external IdP to authenticate and authorize access to Google Cloud." (Source 1.1)

"Using Workforce Identity Federation is the most secure and efficient way to give external users access. Because authentication is handled by the external IdP, access is automatically revoked or suspended if the user is deactivated in the partner's IdP." (Source 1.2)

Option C would require your organization to manage the partner identities, violating the requirement for the partner's IdP to control the access lifecycle.