Cloud IP Address Planner

Cloud IP Planning Across Providers

Each major cloud provider has distinct subnetting conventions and constraints. AWS requires VPCs with CIDR blocks between /16 and /28, distributes subnets across Availability Zones (AZs) in a region, and reserves the first four and last IP addresses in each subnet. Azure Virtual Networks (VNets) follow similar CIDR rules but use Availability Zones differently, with subnets scoped to a single region and service endpoints. Google Cloud VPCs are global resources, with subnets being regional, and Google uses a different approach to private IP allocation with no broadcast domains.

Our cloud IP planner adapts to each provider's model. For AWS, you specify the number of Availability Zones, and the planner distributes each segment's device count across zones evenly. Azure uses a simpler flat subnet structure without automatic AZ distribution, while GCP adds a region selector for subnet scoping. The planner applies provider-appropriate growth percentages (20% for AWS, 10% for Azure, 15% for GCP by default) and generates a table of planned subnets with CIDR blocks, network addresses, prefix lengths, and usable host counts following each provider's conventions.

Best practices for cloud IP planning include using RFC 1918 address space that does not overlap with your on-premises or other cloud networks, reserving contiguous blocks for future expansion, and documenting your VPC and subnet architecture in a consistent format. The planner helps you avoid common pitfalls such as choosing a VPC CIDR that is too small for your expected workload or creating subnet overlaps that prevent VPC peering. As your cloud infrastructure grows, revisiting your IP plan ensures that multi-cloud connectivity and hybrid networking remain feasible.

Multi-Cloud IPAM Strategy

Managing IP space across multiple cloud providers introduces unique challenges. Each provider reserves specific IP ranges for internal services — AWS uses 10.0.0.0/8 for VPC default ranges and reserves 169.254.169.254 for the metadata service; Azure reserves ranges like 168.63.129.16 for DNS and Azure load balancer health probes; GCP uses default-internal IP ranges per region. A global IPAM strategy assigns non-overlapping CIDR blocks per provider and region, with clear subdivisions for production, staging, and development environments.

Overlapping CIDRs are the most common cause of failed VPC peering, VPN tunnel establishment, and Direct Connect circuit deployments. When two connected networks share the same subnet range, routing becomes ambiguous and traffic may fail to reach its destination. Modern cloud networking addresses this through techniques such as private NAT gateways (AWS), Azure Virtual Network Manager, and GCP Private Service Connect. A well-planned IP allocation reserves contiguous blocks for each region (e.g., 10.1.0.0/16 for us-east-1, 10.2.0.0/16 for eu-west-2) and subdivides further per VPC and environment, ensuring clean summarisation and conflict-free connectivity as the organisation scales across clouds.