Enterprise-scale IP address planning

  • 5 minutes

You need a well-planned IP-addressing schema to ensure ease of routing and manageable firewall rules. This unit discusses considerations and recommendations for enterprise IP-address planning in Azure.

Considerations

One of the most critical considerations is to not use an overlapping RFC 1918 (private) IP space with on-premises or other clouds. Keep in mind that Azure reserves five IP addresses for each subnet in a virtual network. Also note that some Azure services, like an Azure ExpressRoute gateway or Azure Firewall, require dedicated subnets.

Recommendations

Plan the cloud IP schema well in advance. Each Azure region should get its own easily summarized range. For example: 10.1.0.0/16 is West US 2 and 10.2.0.0/16 is North Europe.

Make sure to stick with private IP space. Use public IPs only if you own them and are out of private IP space.