Question

Your company owns a public IPv4 range (203.0.113.0/24) registered with your Regional Internet Registry. You are migrating on-premises services to Azure and must retain these exact public IP addresses so external partners' firewall allowlists do not need updating. You need to bring this range into Azure so it can be used to allocate public IP addresses to Azure resources. Which approach should you use?

Accepted Answer

Provision an Azure custom IP prefix (BYOIP) by validating ownership of 203.0.113.0/24, then create public IP prefixes and public IP addresses from the custom IP prefix.

Answer

Create a standard public IP prefix in Azure and manually enter the addresses from 203.0.113.0/24 as static assignments.

Answer

Configure the VNet address space as 203.0.113.0/24 and assign those addresses directly to the NICs of the migrated VMs.

Answer

Create a private DNS zone that maps the service names to the 203.0.113.0/24 addresses so partners resolve to the original IPs.