Cloud NAT for private instances in GCP - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Cloud NAT behavior for private instances

What happens when a private VM instance in Google Cloud tries to access the internet without Cloud NAT configured?

A The VM can access the internet directly using its internal IP address.

B The VM accesses the internet through the default gateway automatically.

C The VM cannot access the internet because it has no external IP and no Cloud NAT is configured.

D The VM uses a shared public IP from another VM in the same subnet.

💡 Hint

Think about how private IP addresses work and what is needed to reach the internet.

Private VM instances do not have external IP addresses. Without Cloud NAT, they cannot translate their internal IP to a public IP, so they cannot reach the internet.

❓ Architecture

intermediate

Choosing the right Cloud NAT configuration

You have multiple private VM instances in different subnets within the same VPC. You want all of them to access the internet using Cloud NAT. Which Cloud NAT configuration is best?

A Create one Cloud NAT gateway per subnet to isolate traffic.

B Create one Cloud NAT gateway and configure it to serve all subnets in the VPC.

C Assign external IPs to all VMs instead of using Cloud NAT.

D Use a VPN to route traffic through an on-premises NAT device.

💡 Hint

Cloud NAT can serve multiple subnets from one gateway.

One Cloud NAT gateway can be configured to serve multiple subnets in the same VPC, simplifying management and reducing costs.

❓ Configuration

advanced

Cloud NAT IP allocation modes

Which Cloud NAT IP allocation mode allows you to specify a fixed set of external IP addresses for NAT instead of using automatically assigned ones?

A Manual IP allocation mode

B Automatic IP allocation mode

C Dynamic IP allocation mode

D Static IP allocation mode

💡 Hint

One mode lets you pick your own external IPs.

Manual IP allocation mode lets you specify your own external IP addresses for Cloud NAT instead of letting Google assign them automatically.

❓ security

advanced

Securing Cloud NAT for private instances

Which of the following is a recommended security best practice when configuring Cloud NAT for private instances?

A Assign external IPs to private instances to bypass Cloud NAT.

B Allow all outbound traffic from private instances without restrictions.

C Disable logging on Cloud NAT to avoid storing traffic data.

D Use firewall rules to restrict outbound traffic even when Cloud NAT is enabled.

💡 Hint

Think about controlling traffic flow even with NAT.

Firewall rules should be used to restrict outbound traffic from private instances to only allowed destinations, enhancing security even when Cloud NAT is used.

❓ service_behavior

expert

Cloud NAT behavior during high traffic bursts

During a sudden high volume of outbound connections from private instances using Cloud NAT, what behavior should you expect from Cloud NAT?

A Cloud NAT automatically scales to handle the increased connections without dropping packets.

B Cloud NAT redirects excess traffic to a backup NAT gateway automatically.

C Cloud NAT queues excess connections until capacity is available, causing delays but no drops.

D Cloud NAT has a fixed capacity and will drop connections exceeding its limit.

💡 Hint

Cloud NAT is designed to handle scaling transparently.

Cloud NAT automatically scales its capacity to handle bursts of outbound connections from private instances without dropping packets, ensuring smooth connectivity.