Private Google Access in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What does enabling Private Google Access on a subnet allow?

Consider a Google Cloud subnet with Private Google Access enabled. What capability does this feature provide to VM instances in that subnet?

A VMs can access the internet directly without any firewall rules.

B VMs can access Google APIs and services using internal IPs without external IP addresses.

C VMs can only access Google APIs if they have external IP addresses assigned.

D VMs can communicate with other VMs in different projects without VPN.

💡 Hint

Think about how VMs without external IPs can still reach Google services.

Private Google Access allows VMs without external IP addresses to reach Google APIs and services through internal IP routing.

❓ Architecture

intermediate

Which architecture supports Private Google Access for on-premises resources?

You want on-premises servers to access Google APIs privately without using public internet. Which architecture supports this?

A Set up Cloud VPN or Cloud Interconnect with a VPC subnet that has Private Google Access enabled.

B Assign external IPs to on-premises servers and access Google APIs over the internet.

C Use a public NAT gateway in the VPC to route traffic from on-premises to Google APIs.

D Configure on-premises servers to use Google Cloud DNS only.

💡 Hint

Think about private connectivity options between on-premises and GCP.

Using Cloud VPN or Cloud Interconnect with a VPC subnet that has Private Google Access enabled allows on-premises resources to access Google APIs privately.

❓ security

advanced

What security risk exists if Private Google Access is enabled but firewall rules are too permissive?

If Private Google Access is enabled on a subnet but firewall rules allow all egress traffic, what is a potential security risk?

A VMs will lose internal network connectivity.

B VMs will be unable to access Google APIs due to firewall blocking.

C VMs might access unauthorized external internet services, bypassing intended restrictions.

D Private Google Access will disable all firewall rules automatically.

💡 Hint

Consider what happens if egress traffic is not controlled.

Permissive firewall rules can allow VMs to access external internet services beyond Google APIs, increasing attack surface.

❓ service_behavior

advanced

What happens if Private Google Access is disabled on a subnet with VMs lacking external IPs?

VMs in a subnet do not have external IP addresses. Private Google Access is disabled. What is the expected behavior when these VMs try to reach Google APIs?

A VMs cannot reach Google APIs because they lack external IPs and Private Google Access is off.

B VMs reach Google APIs through internal IP routing automatically.

C VMs access Google APIs via a default NAT gateway without Private Google Access.

D VMs can access Google APIs only if firewall rules allow all egress.

💡 Hint

Think about how VMs without external IPs connect to Google services.

Without Private Google Access or external IPs, VMs cannot reach Google APIs because there is no route for the traffic.

✅ Best Practice

expert

Which is the best practice to securely enable Private Google Access for multiple projects in an organization?

You manage multiple GCP projects in an organization. You want to enable Private Google Access securely and consistently across projects. What is the best practice?

A Use Cloud NAT in each project and disable Private Google Access.

B Enable Private Google Access individually on each project’s subnet without central control.

C Assign external IPs to all VMs and disable Private Google Access to simplify management.

D Use Shared VPC with centrally managed subnets having Private Google Access enabled and restrict IAM roles accordingly.

💡 Hint

Consider centralized network management and security controls.

Using Shared VPC allows central control of network resources including Private Google Access, improving security and consistency.

Practice

1. What is the main purpose of Private Google Access in Google Cloud?

easy

A. Provide a VPN connection between Google Cloud and on-premises networks

B. Allow VMs with only private IPs to access Google APIs without using the public internet

C. Allow external users to access Google Cloud resources securely

D. Enable VMs to have public IP addresses automatically

Solution

1. Step 1: Understand Private Google Access purpose

   It allows virtual machines without public IP addresses to reach Google APIs and services securely.

2. Step 2: Compare options with this purpose

   Only Allow VMs with only private IPs to access Google APIs without using the public internet describes this feature correctly; others describe unrelated features.

3. Final Answer:

   Allow VMs with only private IPs to access Google APIs without using the public internet -> Option B

4. Quick Check:

   Private Google Access = Secure private VM API access [OK]

Hint: Private Google Access = private VM access to Google APIs [OK]

Common Mistakes:

• Confusing Private Google Access with VPN or public IP assignment
• Thinking it allows external user access
• Assuming it provides public IPs automatically

2. Which configuration enables Private Google Access on a subnet in Google Cloud?

easy

A. Set private_ip_google_access = false in the subnet settings

B. Enable firewall rule to allow all traffic

C. Assign a public IP to all VMs in the subnet

D. Set private_ip_google_access = true in the subnet settings

Solution

1. Step 1: Identify the correct subnet setting for Private Google Access

   The subnet must have private_ip_google_access set to true to enable this feature.

2. Step 2: Review options for correctness

   Only Set private_ip_google_access = true in the subnet settings correctly sets private_ip_google_access to true; others disable it or are unrelated.

3. Final Answer:

   Set private_ip_google_access = true in the subnet settings -> Option D

4. Quick Check:

   Enable private_ip_google_access = true [OK]

Hint: Enable private_ip_google_access = true on subnet [OK]

Common Mistakes:

• Setting private_ip_google_access to false
• Thinking public IPs are required
• Confusing firewall rules with Private Google Access

3. Given a VM in a subnet with private_ip_google_access = true and no public IP, what happens when it tries to reach https://storage.googleapis.com?

medium

A. The VM accesses the URL through Private Google Access without using the public internet

B. The VM accesses the URL only if a VPN is configured

C. The VM cannot reach the URL because it has no public IP

D. The VM must use a NAT gateway to reach the URL

Solution

1. Step 1: Understand Private Google Access behavior

   With private_ip_google_access enabled, VMs without public IPs can reach Google APIs like storage.googleapis.com privately.

2. Step 2: Analyze options based on this behavior

   The VM accesses the URL through Private Google Access without using the public internet correctly describes this private access; others incorrectly deny access or require VPN/NAT.

3. Final Answer:

   The VM accesses the URL through Private Google Access without using the public internet -> Option A

4. Quick Check:

   Private IP VM + private_ip_google_access = private API access [OK]

Hint: Private IP VM with private_ip_google_access can reach Google APIs [OK]

Common Mistakes:

• Assuming no access without public IP
• Thinking VPN or NAT is mandatory
• Confusing Private Google Access with general internet access

4. A subnet has private_ip_google_access set to false. A VM without a public IP in this subnet cannot reach Google APIs. What is the best fix?

medium

A. Create a firewall rule to allow all outbound traffic

B. Assign a public IP to the VM

C. Enable private_ip_google_access = true on the subnet

D. Configure a VPN to Google Cloud

Solution

1. Step 1: Identify cause of no access

   Private Google Access is disabled, so private IP VMs cannot reach Google APIs.

2. Step 2: Choose the best fix

   Enabling private_ip_google_access on the subnet allows private IP VMs to access Google APIs without public IPs.

3. Final Answer:

   Enable private_ip_google_access = true on the subnet -> Option C

4. Quick Check:

   Enable private_ip_google_access to fix private VM API access [OK]

Hint: Enable private_ip_google_access = true to fix private VM API access [OK]

Common Mistakes:

• Assigning public IPs unnecessarily
• Adding firewall rules that don't affect Private Google Access
• Thinking VPN is required for Google API access

5. You have two subnets: Subnet A with private_ip_google_access = true and Subnet B with it set to false. A VM in Subnet B without a public IP needs to access Google APIs securely. What is the best approach?

hard

A. Move the VM to Subnet A or enable private_ip_google_access on Subnet B

B. Assign a public IP to the VM in Subnet B

C. Set up a NAT gateway for Subnet B

D. Create a firewall rule allowing access to Google APIs

Solution

1. Step 1: Understand subnet settings impact

   Private Google Access must be enabled on the subnet for private IP VMs to reach Google APIs.

2. Step 2: Evaluate options for secure access

   Moving the VM to Subnet A or enabling private_ip_google_access on Subnet B ensures secure private access without public IPs.

3. Step 3: Consider security and best practice

   Assigning public IPs or NAT gateways exposes the VM to public internet, less secure than Private Google Access.

4. Final Answer:

   Move the VM to Subnet A or enable private_ip_google_access on Subnet B -> Option A

5. Quick Check:

   Enable private_ip_google_access or move VM for secure private API access [OK]

Hint: Enable private_ip_google_access or move VM to subnet with it enabled [OK]

Common Mistakes:

• Assigning public IPs unnecessarily
• Relying on firewall rules alone
• Ignoring subnet configuration for Private Google Access