Enforce non-overlapping private IP address ranges in all private address spaces where they are connected

Effectively planning your network topology is critical for maintaining workload reliability across environments. Ensuring non-overlapping private IP address ranges mitigates conflicts, facilitating seamless connectivity between different systems and environments, and enhancing overall network stability.

Best Practices

Enforce Non-Overlapping Private IP Address Ranges

• Establish a standardized IP addressing scheme: Design a global IP address plan that includes defined ranges for each environment (e.g., VPCs, on-premises, and other cloud providers). This helps avoid potential overlaps during future expansions.
• Document and maintain an IP address management (IPAM) tool: Use an IPAM solution to track allocated IP addresses clearly and manage the address space effectively. This is critical in larger environments to prevent conflicts and to document the current usage.
• Utilize VPC peering and VPN planning: When connecting multiple VPCs or on-premises environments, ensure that the private IP address spaces do not overlap to avoid routing issues.
• Implement a conflict resolution process: Create a procedure for resolving IP conflicts when they arise, including designating a team to handle IP allocation and de-confliction.
• Regularly review and update your IP plan: As your environment changes, periodically revisiting and revising your IP address plan ensures that it continues to meet the needs of your workloads, thereby ensuring reliability in connectivity.

Questions to ask your team

• Have you established a standard procedure for allocating private IP address ranges across all your environments?
• How do you document and track IP address ranges to prevent overlaps?
• What processes are in place to address any potential IP address conflicts when integrating new environments?
• Are there guidelines to ensure consistency in IP address management across all teams involved?
• How often do you review your network architecture to ensure compliance with IP address allocations?

Who should be doing this?

Network Architect

• Design the overall network topology considering both cloud and on-premises environments.
• Ensure that non-overlapping private IP address ranges are established across all virtual private clouds (VPCs) and connections.
• Develop a strategy for IP address allocation and management to avoid conflicts.
• Document and maintain the private and public IP address schemes used within the organization.

Cloud Engineer

• Implement the network configuration as defined by the Network Architect.
• Manage and monitor the connectivity between different cloud environments and on-premises infrastructure.
• Ensure compliance with the defined non-overlapping private IP address policy during the deployment of new VPCs and services.
• Collaborate with the Network Architect to identify and resolve any network conflicts or issues.

Network Security Specialist

• Assess network topology designs for security implications related to IP address management.
• Implement security policies that align with the network configuration to safeguard private IP address spaces.
• Conduct regular security audits and reviews of network connections and address allocations.
• Provide guidance on securing intra- and inter-system connectivity across cloud and on-premises environments.

IT Operations Manager

• Oversee the deployment and maintenance of network infrastructure.
• Ensure that team members are trained on proper IP address management practices.
• Establish procedures for regularly reviewing and updating IP address assignments and conflicts.
• Facilitate communication among teams regarding network planning and changes to topology.

What evidence shows this is happening in your organization?

• Private IP Address Management Policy: A detailed policy document outlining the procedures for allocating and managing private IP address ranges within the organization to ensure non-overlapping IP addresses across all connected environments.
• Network Topology Planning Checklist: A checklist designed to guide teams in planning network topology, ensuring that all private IP ranges are enforced to be non-overlapping across VPCs, on-premises data centers, and other cloud environments.
• IP Address Allocation Guide: A comprehensive guide that provides strategies and best practices for allocating private IP address ranges, including templates for documentation and tracking resources.
• Network Design Diagram: Visual representation of the network topology that highlights VPC connections and the assigned IP address ranges, ensuring that no overlaps occur between environments.
• Private IP Address Range Matrix: A matrix document that lists all private IP address ranges used by various VPCs and on-premises environments, clearly indicating which ranges are assigned to prevent conflicts.

Cloud Services

AWS

• Amazon VPC: Amazon VPC allows you to create isolated networks within the AWS cloud and helps you define non-overlapping private IP address ranges for your VPCs, which is essential for preventing IP address overlaps.
• AWS Transit Gateway: AWS Transit Gateway enables you to connect multiple VPCs and on-premises networks, managing traffic and ensuring non-overlapping IP addresses across your interconnected networks.
• AWS IP Address Manager (IPAM): AWS IPAM provides a centralized way to manage your IP addresses, ensuring that your private IP address ranges are properly allocated and don’t conflict with each other.

Azure

• Azure Virtual Network (VNet): Azure VNet allows you to create private networks in Azure and configure non-overlapping address spaces for your VNets to facilitate secure communication.
• Azure VPN Gateway: Azure VPN Gateway enables you to connect your Azure VNets to on-premises networks, supporting non-overlapping IP ranges to maintain connectivity without conflicts.
• Azure IP Address Management: Azure provides tools to help manage IP addresses across your cloud environments, ensuring unique address allocation and preventing conflicts.

Google Cloud Platform

• Google Cloud VPC: Google Cloud VPC allows you to create isolated network environments and provides the ability to define custom IP address ranges to avoid overlaps in multi-cloud scenarios.
• Google Cloud Router: Google Cloud Router helps to dynamically exchange routes between your VPC and on-premises network, ensuring that IP addresses do not conflict.
• Google Cloud IP Address Management: Google Cloud offers IP address management features that allow you to efficiently allocate and track your IP address ranges, preventing overlaps.

Question: How do you plan your network topology?
Pillar: Reliability (Code: REL)