Shared VPC concept in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Shared VPC Host Project Role

In Google Cloud, which role must a project have to act as a Shared VPC host?

A The project must be a host project with Network Admin role.

B The project must be a service project with Compute Network User role.

C The project must be a service project with Owner role.

D The project must be a host project with Compute Viewer role.

💡 Hint

Think about which project controls the network resources.

The Shared VPC host project owns the network and requires the Network Admin role to manage it. Service projects use the network but do not own it.

❓ Architecture

intermediate

Shared VPC Service Project Resource Access

Which statement best describes how a service project accesses resources in a Shared VPC?

A Service projects cannot use Shared VPC networks; they only use peered networks.

B Service projects use subnets from the host project's VPC network but manage their own firewall rules.

C Service projects create and manage their own VPC networks independently.

D Service projects use subnets from the host project's VPC network and rely on host project firewall rules.

💡 Hint

Consider who controls the network and security policies.

Service projects use subnets from the host project's VPC network. Firewall rules are managed at the host project level, so service projects rely on those rules.

❓ security

advanced

Shared VPC Security Best Practice

Which practice improves security when using Shared VPC across multiple service projects?

A Grant all users Owner role on the host project to simplify management.

B Use IAM roles to grant least privilege access to service projects for network resources.

C Allow service projects to create their own firewall rules to increase flexibility.

D Disable VPC Service Controls to avoid access restrictions.

💡 Hint

Think about minimizing permissions to reduce risk.

Granting least privilege using IAM roles limits access to only what is necessary, improving security. Owner role grants too many permissions. Firewall rules are managed centrally. VPC Service Controls enhance security.

❓ service_behavior

advanced

Impact of Removing a Service Project from Shared VPC

What happens to the VM instances in a service project when it is detached from the Shared VPC host project?

A VM instances continue running with the same network configuration without interruption.

B VM instances are deleted automatically upon detachment.

C VM instances lose network connectivity immediately and cannot communicate externally.

D VM instances are automatically migrated to a new VPC network in the service project.

💡 Hint

Consider what happens when the network is no longer attached.

When a service project is detached from the Shared VPC, its VM instances lose access to the host project's network and lose network connectivity immediately.

✅ Best Practice

expert

Designing Shared VPC for Multiple Departments

You manage a Shared VPC for multiple departments in your organization. Which design approach best isolates network traffic while using a single Shared VPC host project?

A Create separate subnets per department and use firewall rules to restrict traffic between them.

B Use a single subnet for all departments and rely on VM tags for traffic control.

C Create multiple Shared VPC host projects, one per department, to isolate networks.

D Allow all departments to share the same subnet and firewall rules for simplicity.

💡 Hint

Think about network segmentation within a Shared VPC.

Creating separate subnets per department and applying firewall rules to restrict traffic is the best practice to isolate network traffic while using a single Shared VPC host project. Multiple host projects increase complexity.

Practice

1. What is the main purpose of a Shared VPC in Google Cloud Platform?

easy

A. To automatically back up virtual machines across projects

B. To create multiple isolated networks within a single project

C. To allow multiple projects to share the same Virtual Private Cloud network

D. To enable direct internet access for all projects

Solution

1. Step 1: Understand Shared VPC concept

   Shared VPC allows multiple projects to connect to a common Virtual Private Cloud network managed by a host project.

2. Step 2: Compare options

   To allow multiple projects to share the same Virtual Private Cloud network correctly describes this sharing of a VPC across projects. Other options describe unrelated features.

3. Final Answer:

   To allow multiple projects to share the same Virtual Private Cloud network -> Option C

4. Quick Check:

   Shared VPC = Shared network across projects [OK]

Hint: Shared VPC means sharing one network across projects [OK]

Common Mistakes:

• Thinking Shared VPC creates isolated networks
• Confusing Shared VPC with backups or internet access
• Assuming Shared VPC is per project only

2. Which of the following is the correct way to enable Shared VPC on a host project using gcloud CLI?

easy

A. gcloud compute shared-vpc enable-host HOST_PROJECT_ID

B. gcloud projects add-iam-policy-binding HOST_PROJECT_ID --member=shared-vpc

C. gcloud compute shared-vpc enable --project=HOST_PROJECT_ID

D. gcloud compute networks create shared-vpc --project=HOST_PROJECT_ID

Solution

1. Step 1: Identify correct gcloud command for enabling Shared VPC

   The command to enable Shared VPC on a host project is 'gcloud compute shared-vpc enable-host'.

2. Step 2: Check options

   gcloud compute shared-vpc enable-host HOST_PROJECT_ID matches the correct syntax. Others are incorrect commands or unrelated.

3. Final Answer:

   gcloud compute shared-vpc enable-host HOST_PROJECT_ID -> Option A

4. Quick Check:

   Enable Shared VPC host with 'enable-host' command [OK]

Hint: Use 'enable-host' to activate Shared VPC on host project [OK]

Common Mistakes:

• Using 'enable' instead of 'enable-host'
• Confusing IAM binding with enabling Shared VPC
• Trying to create a network instead of enabling Shared VPC

3. Given a Shared VPC setup where Project A is the host and Project B is a service project, what happens if a VM in Project B tries to use a subnet from Project A's Shared VPC?

medium

A. The VM can use the subnet and communicate within the Shared VPC network

B. The VM creation fails because subnets cannot be shared

C. The VM uses a default subnet from Project B instead

D. The VM gets an external IP automatically

Solution

1. Step 1: Understand Shared VPC subnet usage

   In Shared VPC, service projects can create resources using subnets from the host project's VPC.

2. Step 2: Analyze VM subnet assignment

   VM in Project B can use Project A's subnet and communicate within the shared network.

3. Final Answer:

   The VM can use the subnet and communicate within the Shared VPC network -> Option A

4. Quick Check:

   Shared VPC allows subnet sharing for VM networking [OK]

Hint: Service projects use host subnets for VM networking [OK]

Common Mistakes:

• Assuming subnets cannot be shared
• Thinking VM defaults to service project subnet
• Confusing external IP assignment with subnet usage

4. You configured a Shared VPC but a service project cannot create VM instances using the host project's subnets. What is the most likely cause?

medium

A. The host project does not have any subnets created

B. The VM instance name is invalid

C. The service project is not linked to the host project

D. The service project lacks the 'compute.networkUser' role on the host project

Solution

1. Step 1: Check permissions for service project

   Service projects need 'compute.networkUser' role on the host project to use its subnets.

2. Step 2: Verify linkage and subnet existence

   While linkage and subnets are important, lack of permission is the most common cause blocking VM creation.

3. Final Answer:

   The service project lacks the 'compute.networkUser' role on the host project -> Option D

4. Quick Check:

   Missing networkUser role blocks subnet use [OK]

Hint: Check 'compute.networkUser' role for service project [OK]

Common Mistakes:

• Ignoring IAM roles and permissions
• Assuming linkage alone is enough
• Blaming VM name instead of network access

5. You want to design a secure environment where multiple teams have their own projects but share a common network with strict firewall rules managed centrally. How does using Shared VPC help achieve this?

hard

A. It requires each team to create their own VPC and manage firewall rules independently

B. It centralizes network management in one host project while teams use service projects for resources

C. It automatically applies firewall rules per project without central control

D. It isolates each team's network completely with no sharing

Solution

1. Step 1: Understand Shared VPC central management

   Shared VPC lets you manage network and firewall rules centrally in a host project.

2. Step 2: Analyze team project usage

   Teams use service projects to create resources but rely on the shared network and firewall rules from the host project.

3. Step 3: Compare options

   It centralizes network management in one host project while teams use service projects for resources correctly describes this central control with resource separation. Other options describe isolation or decentralized management.

4. Final Answer:

   It centralizes network management in one host project while teams use service projects for resources -> Option B

5. Quick Check:

   Shared VPC centralizes network and firewall control [OK]

Hint: Shared VPC centralizes network, teams use separate projects [OK]

Common Mistakes:

• Thinking Shared VPC isolates networks fully
• Assuming firewall rules are per project automatically
• Believing teams manage their own VPCs independently