An enterprise architecture team is designing a Virtual Private Cloud (VPC) network in Google Cloud to establish a hybrid connection with an on-premises data center via Cloud VPN. The on-premises network uses the private IP block 172.16.0.0/16. The cloud workload requires deploying standard Compute Engine virtual machines in us-central1 and a Google Kubernetes Engine (GKE) private cluster in us-east1. Which TWO subnet design and IP address planning requirements must be met to ensure valid network routing and prevent IP address collisions?
- Create the VPC network in custom mode to explicitly define regional subnets and avoid IP address overlap with the on-premises 172.16.0.0/16 range.Answer
- BDeploy the VPC in auto-mode so that default regional subnets automatically expand their primary CIDR blocks into 172.16.0.0/16 when IP capacity limits are reached.
- Allocate disjoint CIDR blocks for the primary subnet range and the GKE secondary ranges (Pods and Services) in us-east1 that do not overlap each other or the on-premises network.Answer
- DDefine secondary IP ranges for GKE Pods within the existing primary subnet CIDR block to conserve overall private IP address space.
Answer
The correct requirements are creating the VPC in custom mode to prevent IP overlap with on-premises address spaces, and allocating disjoint CIDR blocks for the primary subnet range and GKE secondary ranges in us-east1.
Custom mode VPCs are necessary when integrating with hybrid networks because they allow administrators to explicitly define subnet CIDRs, avoiding collisions with on-premises ranges such as 172.16.0.0/16. Additionally, GKE private clusters mandate that secondary IP ranges assigned to Pods and Services must be non-overlapping, distinct CIDR blocks separate from the primary subnet CIDR and any hybrid connected networks.
Step-by-Step Solution
Key Concept
Custom Mode VPC Design and GKE Secondary IP Range Allocation